No happy stories here. Tri Star advertised heavily back 6-8 years ago and I order a work station from them. At the time they didn't know whether they were coming or going. Took about 3 tries to get the correct configuration, but at least the computer worked.
I then bought an 'off the shelf' Sony Vaio at CompUSA which other than the stupid Millenium OS from Microsoft, the fact that they don't give you actual OS CD's, and the 'Sony' power supply would cost about $300 to replace it has been a good computer. Still is running - the only comp I have on the internet. Wipe the hard drive every 2-3 years, reinstall W2K and keep going.
Then I went to a local supplier and had them build a workstation for me. Took a year to figure out the memory couldn't handle the heat while rendering. After that the computer has run well except now the capacitors on the MoBo are starting to bulge which probably means its life is limited.
After the nightmare at the local supplier, I went with Xi Computer. That has been a 3-4 year joke. Just figured out this summer that they mixed memory on my MoBo which is not good on a dual processor I have been told. This not only screwed up my video card but caused the computer to constantly crash. Among a alot of things issues with Xi, the most annoying is that they NEVER logged a single call into tech support. So everytime I called to try to resolve things or start trouble shooting a new issue, they were starting blind. Unbelievable. I am going to send the memory and video card back but based on the last conversation I don't expect much. They said it was too late to do much of anything. It was too late because the idiots at tech support did not have a clue what was going on. Given the status of their tech support I doubt they would ever have been able to solve the problem if I did not tear things apart on my own and isolate the problems. Of course I could have sent the $3,500 computer back after I had it for week but when you blow that much you count on the fact that they built it correctly, that it will work and usually you can't afford to loose it when you should be making money.
My recommendation - by cheap at the middle of the tech curve and expect it last a few years. After that something will be on its way out, memory will no longer be available, or there will be some new standard that will let the next generation of systems run an order of magnitude faster.
Another associate that I work with did not have good luck with Dell - all they new how to do (not very well) was swap components. But at least he did not have to send the thing back and someone else dealth with the issues.
Good luck, I certainly haven't had much.