It would actually be great to hear your findings!
One other note, the graphing pages are still using legacy JSF charts, and they are slow to render. I thin RHQ 4.7 will see those replaced with much better charting. As for server load generated by clients (like browser sessions), we may need to look into that. I don't think a large number of GUI sessions has actually been something we've focused on up to this point.
For what it's worth, I like to use Chrome with RHQ.
It definitely seems so far that Chrome/Chromium is the fastest to use with RHQ. Pages seem to fly when clicking around the UI, and memory use is lower than in Firefox.
Firefox works fine but is a bit heavy on load and memory as said.
IE6 is not working at all, so no surprise there - IE8 & 9 works fine though, but I don't use them.
Opera does not work at all - which is a shame since I am partial to Opera and know its JS implementation is fast.
Anyhow that's our findings so far unless someone's got any other suggestions.
Update September, 2013:
Chrome/Chromium is the fastest with IE10 in second and FireFox ESR (Download: https://www.mozilla.org/en-US/firefox/organizations/all.html) trailing closely behind. FireFox renders the content the most accurately although at slightly higher resource usage. Notice I mentioned FireFox - Extended Service Release and not normal FireFox. FireFox ESR is the more stable corporate release and is my personal pick for RHQ use -- it is slightly slower but visually, the components from smartGWT render without any glitches.
As for Opera, we don't compile GWT for Opera. [If you made a big enough fuss we could probably add this in -- maybe. At the expense of larger binaries and increased compile time.]
We also don't compile for IE6 as it is just abysmal and IE8 is supported but very slow, as its rendering engine is just way behind the modern browser. IE9+ is recommended. Also the d3 graphing library will not render on IE8, so while you can still use the app the menus for graphing features are disabled for IE8.
Of course, we support most all browsers, this is just a recommendation of what's best for using RHQ.
Thanks for that Mike!
I am pretty sure we can live without Opera 12 support, besides they are moving to Chrome as well for their engine. And currently it is just Chrome with the Opera logo so makes no difference really...
We use IE 10 and Firefox as well so as long as you compile for those it's golden.