@newoceans - Actually the answer is yes and no. Right now I have both LLA and BPS running on one site. Although the devs recommended that only BPS be used, there doesn't seem to be any conflicts and both seem to be working okay.
The site in question came under a very heavy attack recently, running LLA numbers up past 2,000 in one day. To reduce the load on the server I renamed the WP Login file so that it wasnt apparent that it was a WP site. The file name reverted back to normal when it updated to WP v4.0. The attacks are not as heavy now, but LLA still shows as many as 100/day and BPS shows about the same number, close to 1,000 in a couple of weeks.
Since that particular site was hacked once (via an old template vulnerability) I suspect its on some bad guy's lists. Being that it's so "popular" with the bots but hasn't been hacked since that first time last year I'm hesitant to remove LLA. More superstition than anything I suppose...but if it ain't broke...
Hope that helps!