The latest update in my case is not lagging but is slower to load up, even with a SSD. Is your X-Plane 11 on a spinning disc drive (I don't know the proper term for older HD's)?
I would say though in my case the FPS might be slightly better with 11.00R1. It looks like X-Plane may not give good results unless on a SSD. If your using Windows OS, the HD can become fragmented. That can slow access to loading data. There is a defrag program in Windows that can take care of that. Another thing is if your RAM is not enough Windows and X-Plane may start using vitual RAM. That means swapping data in and out from the HD. You might be able to tell by looking at the HD led light on your computer. Is is going flat out, constant blinking?