The cluster provided by Advanced Clustering Technologies offered an excellent trade-off between cost and performance, together with competent technical assistance from the seller.
We purchased Cowboy from Advanced Clustering in 2012 and it has been an invaluable resource to the HPC community at Oklahoma State. The engineers and techs at ACT work with us to continuously improve this, most recently with the addition of their job submission software, eQUEUE. We have been thoroughly pleased with how products and service from Advanced Clustering just work.
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.
I've never had such consistent high quality support and service from any other company. You guys are fantastic! You rock!