I don't know if my experience/knowledge will help, since it's all in the UPS products.
TrippLite is well known for their UPS products. In that space you inevitably get comparisons with APC, which makes top of the line, very reliable UPSes. At some point, TrippLite started shipping UPS drivers for linux, which brought them a lot of business, and is what made me buy their UPS. At first, a lot of people were wary of TrippLite because their products are not top of the line. I think they've proven themselves, as long as you keep in mind that they *are* in fact *not* making top of the line stuff. Their prices are accordingly attractive.
For comparison, their ratings aren't the same as APC. The same power handling capability rated at 650VA by APC would be rated about 1000VA by Tripplite. Also, my TrippLite UPS usually run hot, which is probably because of their smaller case, lighter weight, smaller parts, etc.
To sum up my personal opinion, I'd buy their products, but only if I didn't mind settling for less than top quality. I'd also be careful to derate their specifications. Where money is the overriding concern, their products are certainly not junk. And there's plenty of junk out there.