My best time is 25.1, I'll believe it, since it was on the computer, It's faster to aim at targets which is one of the biggest time wasters.
Ok, here's the pic for proof. I actually did much better this time around (almost a full second faster) And here's the spec ops version*edit* only got 21.95seconds in solo
24.75 seconds. i think its easiest with the m9 the whole time, no primary. more accurate and controlled.
IMO m9 first then switch to USP-tactical knife on the way up the stairs (so your knife action finishes faster, thus allowing you to start shooting at the next set of targets more quickly).