When I first started looking at how to configure Cowboy to provide the optimum HPC resource for our campus, the engineers at Advanced Clustering took the time to go through the various processor and storage technologies to see which ones offered us the best price/performance. We have been thoroughly pleased with ACT’s products and service.
I've recommended ACT systems and tech support to a number of colleagues and have received nothing but thank-you's after purchase.
ACT is essentially unique in that they are very knowledgeable and "hands-on" with respect to their products and service...they truly enjoy rolling up their sleeves and solving technical problems!
By the way, I probably have said this before, but Billy is awesome. RMA's can be such a pain with some companies, but he makes it painless.
The short story is that I love the ACT cluster. On every major account including quality, price, management and fun, our cluster scores very high. We have a low number of users and they are all very smart. That makes clustering much more easy and fun.