A few people have had run-ins with them but generally people seem pretty pleased with them.
I've ordered from them 6-8 times and have been very pleased every time and I've talked to them 2-3 times on the phone and found them helpful and very friendly.
I've heard mixed experiences regarding TQ which has made me question buying from time to time. I have had no problems. Never had to contact so I can't speak about customer service, but I always get exactly what I ordered in a timely fashion.
I've placed several orders with them recently and was very pleased. Fast shipping and great customer service. Several questions I had were answered quickly.