-The Crown's are ok units (just don't believe all the propaganda).
-The Yales are ok, just keep the load-wheel shackles well greased (I've seen worn-out shackles in as little as 27 hours!) (BTW, installing bushings solves the problem)
-I'm not a fan of the Raymonds (too fancy & overly complicated for a walky jack that is going to see a ton of abuse IMHO)
-I assume the Cat is a rebadged Junheinrich (sp?), so there may be issues with parts and service (at least here there is anyway)

You should mainly base your choice on dealer support.
It's always fun to buy the cheapest (or even most expensive) unit, only to have it sit for weeks at a time whenever it breaks down.