About a year ago I registered at DNSimple to check out their services, because I was frustrated with my current registrar/DNS host (1and1.) One of the owners must have noticed I registered but didn't buy anything, because he contacted me to ask if there was anything in particular I needed. I appreciated the courtesy and told him I'd switch over when my domain neared expiration... and when the time came, I did!

Honestly I don't have enough experience with them to really evaluate their services, but they seem trustworthy and competent, and I like working with people I know I can talk to.