Honestly the customer service experience varies among carriers. I honestly don't believe any carrier is better than the next. It's all about your experience. I've heard both Sprint and Verizon have poor customer service and I've been happy with both.
This may be because I've worked in wireless in the past so I know what to expect and what not to expect.
Either way, certain things I can deal with if the service is great. I'd rather hit 90 Mbps than the 2 I hit most of the time now. In some areas it's much better than others. But overall, Sprint has a lot of work to do. My iPad with Verizon is consistently performing better than my Sprint iPhone.