I also bought an R5 about 5 months ago (end of Feb) but don't find the ride twitchy. The only few times I've had to keep a good grip is when the crosswinds are strong, but that could be due to my light wheelset (Firecrest 303). I'm riding a mixture of flats and rolling hills so spend the majority of time on the drops, but don't feel like I'm in a death grip. I also switched out to a longer stem so I could get lower and more aero, so is the ride twitchy when you're in the drops?