LEGO

I have quite a bit of experience by now. I had heard increasingly good things about Lego competitors, and wanted to get my own impression. In addition to that, I was growing more and more frustrated with Lego's decreasing quality (and still am, btw). So that's why I got my first non-lego sets.

My experience so far has been pretty positive. If you do a bit of research beforehand, it's pretty easy to avoid the crappy stuff.

• Piece quality: everything that uses Gobricks pieces is gonna be extremely high quality, higher than Lego in most regards. The clutch power is stronger than Lego though, so stacking plates can be a bit dangerous. Gobricks pieces are used by a lot of brands, including Mould King and Funwhole for example. For other brands, a bit of research will tell you what to expect in terms of brick quality.
• Set quality: how well the sets are designed of course varies wildly, but there's lots of really awesome stuff out there. Another field where a little research will go a long way. There is a lot of stuff you would never get from Lego, for example Funwhole only does sets with fully integrated, nicely thought through custom lighting kits.
• Legality/Morality: There's lots of brands that just do their own stuff, which is nice and unproblematic. Some brands, like Mould King, apparently sometimes use MOC designs without the creator's permission, which I try to research beforehand and not buy those sets if that's the case. Some use IPs like Star Wars without proper licensing, or flat out steal set designs from Lego, which, idk, not that great but also I don't really care about big corporations losing money over that.

Overall, I would say it's a little harder to know what you're getting compared to Lego, even within the same alternative brand. You have to put in a little more research effort, but imo, it's absolutely worth it, not even only looking at the price.

Edit: Just noticed I should probably provide some examples of what I've actually tried so far. Give me a sec.

Edit 2: Alright, here's a couple examples so far:

• Mould King Botanical Garden. This was the first major set I got, really happy with it. It's a MOC, but officially licensed from the designer. Looks awesome, lots of details. Construction is a little flimsy at times, but it's Gobricks pieces so it still holds together very well.
• Funwhole Lakeside Lodge This one is just awesome. Looks amazing, interesting build. Also Gobricks pieces, although I would have preferred the lower clutch power of Lego pieces here since it's a lot of plate stacking.
• Sembo Flowers Got a couple different flowers from Sembo, they were all good. I think they're also Gobricks, but not 100% sure - the clutch power at least had no trouble keeping together the somewhat delicate builds. There were a couple of 1x1 half round tiles that seemed to be slightly mismolded here, but everything still worked.
• BlueBrixx Pro Reichstag Berlin First non-Gobricks set in this list. The design is cool, but the brick quality was a bit lacking, quite a few mold problems in there. Still held together and looks good, though!
• Forange Triceratops Egg Very cute build, no problems with the pieces.
• Cobi Boeing 787 Cobi produces their own bricks (in Europe, no less!), and has lots of special shapes you don't get from Lego, as they are much closer to model building, with basically no emphasis on play. There's no stickers in this set, and the prints are incredibly high quality, no comparison to Lego at all. It's all more specialized, though, so not that great for people who like to take apart their sets and build something else with it. Their tiles don't even have grooves for the sake of a sleeker look, so they're really hard to get apart again.
• Panlos Mini Street View Cinema Nice design, again, nothing to complain about with the bricks.

Got a couple more, but I'm getting tired of listing these. Open for questions if anybody's interested!

I've only bought non-Lego once to get some Star Trek sets which I believe were produced by kre-O. Not the best quality building blocks, and I wouldn't recommend them. I really wish Lego had the Star Trek license so we would get some epic sets.

My only experience was my grandparents once getting me a bucket of Megablocks when I was a kid - probably late 90s/early 2000s. Things have probably improved since then, but these things were awful. The plastic was dull, colors were pale, and they bent easily - getting those white crease marks. It was also my first lesson in tolerances, because the tolerances were also awful on them. They were inconsistent, and many were too loose to tightly connect to each other or real Lego. My grandma was also very disappointed and went back to buying the real stuff for future birthday presents!

I got the yellow Fiat second hand and it was fake. Didn’t take the right precautions and got scammed. It was cheap (~$25) so I can’t complain. The quality is noticeably worse than original Lego. The snap is way too strong and the finish is weirdly matte. It was so hard to disassemble.

When built, only a collector would notice but the building experience wasn’t enjoyable and I’ll probably get rid of it or sell it again with stating it is not original Lego.

I bought some nonlego sets. Some where straight up copies, some where their own designs i think. What lead me to it was the price. I bought a second hand ucs falcon for around 500/550€. If you want to build the bigger sets like the UCS ones, you really have to spend a fortune. Its ridicoulos (will never spell it right). I.e. the NES is around 250€ or like 65€ as a clone. Or the Stranger Things Set. More or less the same. But if im looking to buy a set, im first checking the lego price on Idealo or so. And im looking how much it is on eBay. I.e. i bought the lego batmobile 89 from eBay as im not afraid of buying used sets. Some sets i only buy for the build. Like Ninjago City gardens. If i was rich, i would only buy lego i guess. But as im not......

For me, its always been about price and my experience has varied from set to set.

My first was the girls 2016 ECTO1. One brick had a mould flaw but it was internal and couldn't be seen once completed. One of the girls hair was wrong and the prints for the proton packs 2x2 dome wasn't straight. Finally, the yellow transparent cylinder for the roof light was cloudy rather than crystal clear. Apart from those qwerks, I'm happy with the set.

I bought a clone of the mini figure scale Batman Tumbler which was fine no defects. The only problem was where they compressed two instructions onto a single page in the manual which made it fiddly to build at times, especially with all black bricks.

Another was the technic Lego Batpod which I bought because the real Lego was a limited edition gift to those who bought the UCS Tumbler I believe. Some of the technic pieces were a tight fit and the clutch was a little weak. That model was quite fragile.

The final one I bought was the minifigure scale Tim Burton batmobile because again, the Lego version was an exclusive to those who bought the UCS Batmobile. No complaints, great little car.

I tried one time, I bought an off-brand on aliexpress for the wall-e model. It is super impressive and quality is top notch. I guess YMMV, but I was really pleased with this one.