One pound lighter, simpler set up by far. Better re-sale, big coolness factor. The jets are simple engines, with incredible fine refinements. The new computer software which brought this much improved high speed flow efficiency about is way ahead of its predecessors. There will be more small refinements , but this is a big jump. The price isnt much more, and if you must, wait a month just to see. But only do the older engine if its a gift, or near give away price. Havnt heard any regrets yet on everything describing the P100RX. I hope mine comes in next week.