The only reason to go original is if you're particularly attached to the Pinnacle Station dlc from ME1. Mod-wise, there's still a bit more for OT than LE, but LE is starting to pull ahead, especially with the larger mod packs. I also noticed LE was more stable with mods like ALOT. (I'd get horrible shadows and red eyes with the original version, even though I installed everything in the right order.)
LE also has the benefit of not having to reapply any DLC, and graphics overhaul of ME1 is still quite stunning, especially compared to the original.
That said, you would have to start fresh with your saves. If you only care about ammo/weapon upgrades, then it's nothing you can't fix with a save editor.