main difference talaga yung 3 valve engine. mas matipid, mas efficient, mas may power.
but for a 150cc vespa lx, power is enough, matipid na din naman. Personally i wouldn't buy the 3v for double the price, pareho lang naman imho.
First to consider when buying a vespa lx for commute is the rear rack where you could install a topbox. The underseat storage of the lx is not that big, kailangan mo talaga ng ibang lalagyan. Maraming brands ng racks, but the best is still from piaggio. Meron din from Givi (fixed rack) and other companies like cuppini, etc.
Topbox brand, GIVI would still be the best option. Available na yan through motoworld (nationwide).
Another thing to consider is the windshield. Hindi pang-porma lang ang windshield. It actually deflects dirt, insects, etc. away from the rider. Lalo na kapag umuulan, yung dirty mist, nadedeflect nya kaysa tumama sa iyo directly.
For helmet, I would recommend the LS2 jet helmet na may faceshield. Kung hindi ako nagkakamali, ito lang yung helmet na may shield na kasya sa underseat storage ng lx, other brands ng jet helmets with shield like nolan, agv, hindi talaga kasya.
and dont forget to consider buying a nice raingear. Nice, ibig sabihin breathable material at hindi yung cheap materials lang na madaling masira at walang vents.
Goodluck with the purchase! I have an LX too and I used it everyday to work. Masarap gamitin!