It's pretty bad. I did some research before putting 55w in mine and only found one thread showing pics of burnt minih1 bowls and it was the 5.0 or older bowls. Never seen any 6.0 bowls like what we have get burnt. 
I knew they were <5.0 bowls because they didn't have the step on the bowl. But I guess most people listen to the majority when they preach to not put 55w in the minis. 
For me, 35w was fine...but I craved more and decided to roll the dice. Gotta remember, my ballasts are cheap Ebay ones which I'm quite sure were putting out under 35w because the 4300k bulbs were cooler white than I thought they should be, closer to 5500/6000k. Now with the cheap 55w ballasts, it's a warm white like I'd expect. Maybe a little warmer than 4300k but I like it. 
If I burn my bowls, oh well. I can replace them. 
And no, Ebay ones can have horrible aiming, I've seen pics where rotation was off about 30 degrees.