It's pretty much the same.
Java is supported out the box in QARun
Winrunner similar to 'C' QARun similar to VB
You can do all the same checks
Both have a type of GUI Map
Both have gui spy's
Both can query databases
Rational Robot and QA Run are very similar, Winrunner is fairly similar and segue different.
QARun comes as part of a better integrated suite.
Literally there is hardly any difference between the two. On price QARun is way better
I prefer Winrunner for web based tests
QARun is easier to learn out the box.
QARun does not have a datatable wizard but Winrunner's is not that great. Rational's datapools are alot better.
Compuware does have a complientary product called FileAid that is fantastic for working with databases.
I have started a comparison of the major tools (Functional) Robot (2001a), Silktest (5.03+ I think), QARun (4.7+), Winrunner (7.0) and Visual Test so far I have completed 20 pages. I believe it will be 100 by the time I've finished if you want a preview of what I've done so far including a tool matrix (my look at what tools win where) then send email to email@example.com. I'll give you what I've done so far then update you when I'm finished. It also has code samples, functions, etc from each product.
I am also doing a performance test tool compare of Loadrunner (7.0), SilkPerformer (4.5 I think), LoadTest (now Test Manager 2001a), OpenSTA sorry no QALoad as I used an old version not the latest so wouldn't be fair. That will come out after the functional one.