Have you looked at how much data you actually use? I use mine a lot and found that there was no need for me to have unlimited data and the smallest 2gb package is fine for me.
You can always call and upgrade it if you see you might go over. I believe even if you go over if you call and upgrade before your bill cycle ends you won't be charged extra.
Before I had Verizon I had Sprint it sucked so bad I switched to nextel and it was great till sprint bought them then it sucked again so I went to Verizon and have had no problems since.