I steered away from the Irwins because I have a friend in the boat
industry that bought about 10 of them to try, and he had a failure rate
of about 60% after using them for about two weeks. He took all the
defective ones back, only to have a repeat performance. The guys where
he bought them told him they were having a lot of problems with them,
and they were going to quit handling them altogether.

I bought some at Sears that were just like the old yellow clamps I
bought years ago (maker unknown) and use them hard all the time. I use
them to clamp down my miter saw on the job, for a quick clamp before
nailing, to let the glue set on a repaired door, to force cabinet
stiles together, etc. Constant use, no problems.

YMMV, but when they are on sale at Sears they are very reasonable.

Robert