Any time you can decrease the size of your kernel its a win IMHO. Typically the less thats there the less there is to possibly be a security risk. The smaller the kernel the smaller the memory footprint. I would recommend you take a snapshot and test both kernels, just seeing the baseline memory usage after boot should be enough to give you an idea. other than the basic footprint of the kernel, I don't think you would see any specific gains unless there happen to be specific patches in the virtual kernel you are looking for.
