Noticed the differences in my 340's maiden voyage as compared to my previous 350 ...
1) Its significantly quicker in the straights and criss crossing. Its also a little quicker when rotating. This results in more coverage area or less time required to cover the same area as my 350. I can actually use less water/detergent to cover the same area as before.
2) It also appears to be able to run longer. On my 350, even filling the clean tank to the brim, it will engage the dry mode at 40 mins. On this 340, at 45 mins, its still in the wet cycle.
3) There are less spots missed with the 340. With my 350 after a full cycle, there will be one or two spots which are missed during the dry cycle, hence the wet patches. With the 340, the result is more consistent and no noticeable wet patches after the full cycle.
4) Cosmetically, the tank is different between a 340 and a 350 from flaps to the design at the bottom.
5) Not sure if its due to wear and tear on my older 350, the 340 appears to be quieter too.
Overall, i'm pretty pleased with the 340's performance.