LOL Im trying to do a 4 but the motivation is a bit behind right now. Im actually quite "OK" with the 99s. If you build the bike right, its a pretty nice platform. I learned a lot building the two 1299s and the V4 is a bunch easier as the cross pollination of parts helps and the development time seems much less. There was a lot of prototyping on the first 99. A lot of hand made pieces and making things work then the whole "guinea pig" for the CDT stuff. My only real gripe with the bike was and is the electronics/electrical system. Its garbage from a quality and modification perspective. Thats the only thing on the 99s I didn't build but i do have a full aerospace spec wiring center now that I could build custom harnesses. Still the inability to hack the ECU/BBS interface and customize it would still be there so I don't know. As far as the bikes themselves go they put out way more power than I could ever use and they don't weigh much. Yea you can get more power and speed out of the 4 but I came to the conclusion that Im just not that skilled like all the others bad ..... talking a out how much more HP they can get out of the 4 hell my Graves R6 scares the crap out of me at times so the 99s are not at all "out to pasture". Put a real radiator in it, a good electronics package and tune it (correctly) get the suspension sorted, toss the masters, get a decent set of pegs bla bla and your still top notch. The guys chasing gimmicks and numbers that have zero significance to them in the real world, well they will always be there. Able you have a great bike (no gimmicks, all business)and you are a good rider. No upgrade needed my friend. A 4 build for me is just a project to tinker with parts and some tech.