With over 1000 virtual zwift miles and 600 outdoor miles on the Vendetta, I feel I can start to post some observations comparing the P-38/F-40 to the Vendetta. I had over 13,000 miles on p-38 and over 400 miles on f-40.
My P-38 weighed about 1 lb less than my Vendetta so weight is negligible, but that's where the comparison ends. The superior aerodynamics turns the Vendetta into a super bike. On the p-38 I used to struggle to stay with the fast guys in my local club and could usually only manage 1 or 2 pulls during a ride. Now on the Vendetta I pretty much pull the entire 2nd half of each ride and can often drop the group if I want to, but I like riding with these guys, so I don't.
https://www.strava.com/activities/960769119
The shop rides so far this season have been far from flat, but haven't included any serious climbs. So I went out and tried a small local mountain climb that includes a 1 mile 9% avg Summit Rd segment with sections in the teens.
https://www.strava.com/activities/955238574
On the steep sections I started experiencing significant front wheel slip. It seemed the only way I could kinda avoid it was to sit up and grab the hoods. Laying back down resulted in immediate wheel slip, which sucks when you're dumping so much power in those sections, but I feel with practice, this problem can be somewhat overcome. I was happy with low speed stability and was able to hold a straight line up the steepest parts. I missed my PR by about 45 seconds. I did have a car block me for a few seconds at the start of the climb. When looking at data from other small steep hills, whenever I end up below 10 mph the difference between the p-38 and vendetta is negligible and might even give the edge to p-38 since you don't get wheel slip and breathing upright may be easier. Surprisingly I find the Vendetta more comfortable after a hard ride, since I used to experience soreness in my lower back from pushing hard against the mesh seat, otherwise the mesh seat of the p-38 does an excellent job of smoothing out the bumps.
I think over most routes the speed of the Vendetta compares pretty equally to a P-38 with just the F-40 nosecone on. But put the entire F-40 fairing kit on the p-38 and it's just in another league on the flats and distance with moderate hills, but throw in winds above 10 mph and its challenging to put the hammer down always trying to be prepared for a gust just to stay upright. My PRs on the Vendetta seem to be mostly roller segments that include a variety of + - 5 % grades.
Overall I'm thrilled with the V and consider myself lucky to have experienced these amazing machines. I must admit, as fun as it is to crush the egos of the fast guys in my area, I do feel like it's cheating showing up on a V20, kinda like showing up to a group ride on a tricked out TT bike. I feel that an R-84 would be much more compatible for mixing it up with DFs. The R-84 is the 20lb carbon fiber version of the p-38. The aerodynamics would be similar to a road bike in the drops, like it was on my '38, and the lighter weight would a much better match on the steep stuff and accelerations. I used to be able to give a pretty decent draft to the short guys on my p-38, tho the tall guys complained. Right now the tall guys make jokes that I'm only giving their ankles a draft and the short guys now have their entire face exposed to the wind. Still most seem to be very impressed with the Vendetta. I think I'll keep her