Peter Guthrie's HDRIs are very bright I find
What I do is open then in photoshop, and add an exposure layer over the top, bring the exposure down a touch
I also resize them to I dunno, 4000 pixels wide
then save this out as a new version
I think he mentions this in his 'faqs'
workstation well past its sell-by-date, Vista 64 bit (!) with a pitiful amount of RAM, re-invigorated with a GX 590
3ds Max Design 2011 (have 2013 but can't be bothered to re-do all the UI), CS5, and that free z-brush program, whatever it's called