I did not measure ground clearance before/after. The tires are easily 3" taller than factory so 1.5-2" ground clearance. Regardless, it visually appears to have a lot of ground clearance now and we have driven over some downed trees that will leave you wondering how it was possible.
Comment: I've owned the Pioneer for about a week. I went in sort of thinking it was a toy more than anything. After the tire change and some further seat time I have decided two things:
1) I cannot believe how much "fun" it is to drive. Taking off at 30mph down your favorite trails is sooo much more fun than I anticipated. Feels like driving a rally car. More fun than an ATV and much better than my giant Polaris Crew, which essentially feels like driving a bus. So expect your riding to be much more fun. Your wife will actually be interested in driving an off-road vehicle. The machine appeals to a wide array of people who will never be interested in driving an ATV.
2) This thing is not a toy. It is very capable off-road. I guess that is the most interesting thing because it looks like a toy, but it is definitely not. Alternately with a 450lb rating on the rear rack the machine is capable of carrying a fully loaded 50 gallon spray rig, which makes it possible to get hours of spray work done that an ATV is not capable of.
My last comment is that people ask me why I didn't get the 700.... So, yeah, I will probably get a 700-4 at some point to replace my Polaris Crew, but the 700 and 500 are completely different vehicles. That question like asking why did I purchase a regular truck when the one-ton-super-extra-long-double-super-crew-cab-long-bed is an option -- because I don't need a gigantic vehicle for every task. Many times smaller is better; in fact, the smallest vehicle that gets the job done is usually best. The 500 is unbelievably nimble and responsive. I didn't expect to like the 500 as much as I do, which is what I noticed most of the professional reviewers saying too and now I get it.
Hope that is helpful.