While this is an old debate, it has become more prominent today, considering that many designers outsource web designs to specialized companies. Finding a reliable long term partner is of key importance here, one who can understand how you want the designs to appear and what kind of features you want. I feel that the question has now started shifting from "whether to outsource" to "how to outsource".

We offer similar service - ButterflyHTML - PSD to HTML Service. Here we are focussed on creating long term relationships with customers. Note that pricing is quite reasonable and we pay a lot of attention on delivering high quality code as per the requirements.