Back in Feb I compared an XRS3 6-36 to the Burris. I no longer have the Bushnell, but the glass comparison was pretty much equal if memory serves. Hard to say for sure, because I never had them together in Mirage conditions.
I believe
@Chickentoast had both a Burris XTR3 and Bushnell XRS3 and said he thought the glass was pretty much a wash. Which means, both are awesome and the two best bargains on the market without a doubt.
I'm sure it darkened a bit at 36X, but I didn't notice it. I know guys who have compared the new Bushnell directly to a 7-35x Mark5HD and it was no contest, the Bushnell is much nicer.