I have the 20 and 40, both with auto-turn cradles and humidity pump. They were used pretty much non-stop last year. I had two problems. First with the internal electronics which seemed to give up the ghost quite quickly on the 20. Brinsea were absolutely no use in helping - even though the incubator was only 6 weeks old because I hadn't sent them the registration card within 30 days of purchase they were totally uninterested in helping. Left a very bad taste as a customer experience. In the end, I was able to return it to the seller for a replacement.
With the 40, the mechanism on the auto-turn cradle seemed to jam and caused the motor to fail. Couldn't be bothered with the hassle of Brinsea customer service again, so just bough a replacement motor and everything is back to normal again.
Apart from the two experiences above, the incubators have been very reliable and in almost non-stop use last year. I think the advantage of Brinsea is that you can easily buy spare parts or interchange parts between incubators, although the spares are very expensive as is their postage costs.
Our success rates rose significantly when we used the humidity pump - worth the extra cost.