Dell or Generic Brand PCs for the Small Business

I am the IT Manager/NetAdmin at a small business with around 50 workstations/laptops and 4 servers. About 3 years ago we purchased custom built PCs from a small local PC shop. I was not too happy with them after about a year. I began the process of replacing these systems with Dells. We purchased 4 Dell workstations and 1 Dell laptop. So far that’s not too many. As we began to replace the rest of the workstations I’m wondering if I should just go with TigerDirect and Systemax and save a few hundred per workstation instead of going with Dell. What should I do? I am the only fulltime technician on-site so I have to handle all the desktop support.

Thanks.
-Matt