I blasted a deer at 95 yards, and a good 20 yards of that was brush, with my 7mm mag this year. As did a buddy. Last year, my dad shot two through about 60 yards of fairly dense brush with his 300 WSM (one of them center-punched a small willow tree on the way there). And a buddy smoked an elk with a 270 as well.
They all worked well, leading me to suspect that the whole 'heavy/slow calibers' as superior 'brush cartridges' myth is complete bunk.
If I *knew* that the longest shot I'd have to take would be <150 yards, I'd probably pack my 500 S&W handi; however, the country I hunt as often as not offers 300+ yard clear shots as well as the occasional brush shot. Therefore, I prefer faster/flatter cartridges.
I could always do go for both heavy and flat by using my 378 weatherby, shooting 300+ grainers at high velocities