Why not giving it a try? I currently working (since a few weeks) on a project with SpringMVC and I have to admit, that imo it sucks. The provided tags are minimalistic (struts offers here much more), the documentation could be better and getting most of the time I have the feeling it's interfering me more than it helps me. Personally I prefer Struts 2. But as I said, give it yourself a try and find out, if you like it or not.
I'm not going to give a point-by-point comparison, but I was a long time Struts developer who switched to SpringMVC. Conceptually, the two frameworks are very similar so there was not much of a learning curve.
For me it came down to the fact that I was starting on a new project that was using Spring heavily, and when it came time to pick a webapp, there was no reason not to use SpringMVC over Struts. SpringMVC feels cleaner and more polished and I just enjoy it more than Struts. I have instructed several developers on SpringMVC and all have found it relatively easy to pick up. YMMV, but for the Spring based apps I've been working on, it's just been easiest to use SpringMVC.