Many of these profilers have been reviewed in the various magazines listed previously. You can usually search the magazine web sites to identify which issue of the magazine provides a review. Often the reviews are available online. The profiler vendors should also be happy to provide pointers to reviews. The annual "best of Java" awards includes a section for profilers (see the Java Developer's Journal).
Borland's OptimizeIt! (http://www.borland.com/optimizeit)
Sitraka's JProbe (http://www.klgroup.com)
PureLoad from Minq Software (http://www.minq.se/products/pureload/index.html)
SockPerf from IBM alphaWorks (http://www.alphaworks.ibm.com/tech/sockperf)
DevPartner Java Edition from Compuware Corporation (http://www.compuware.com/numega/)