Yes I only ran 1 specialist perk (Plus Hardline) so I could get the specialist bonus starting at 3 kills in a row(200 points per kill) You still have to wait to get all perks at 7 though.

I always prestige very fast, top 5000 in MW2, was almost 10th before people even had 10th lobbies, quit MW2 when tools were running around as tenth that they didn't earn.

As fir MW3, can't ge 10th as fast cause I graduated and have a lady. But thus far 2/3nights a week lands me at:

33,000kills

Presitge 8

6Days Played

Play mostly TDM, solo

AVG 30kills per game

So...

48hours for 10th, not possible no matter what.

Prestige 10 level 80. Just under 8 days time played 99% domination. 1.64 KDR 2.23 W/L. 42,000 kills. Mainly play with a team. Domination rank all time #954.

It took me 7 days of gameplay to get there, so I'm sure there are some people who play like a bodybuilder on some serious roids and are able to get there in about 5 days.

To be honest, I thought I was pretty dang fast though in 7 days of gameplay.  I've been a 10th prestige level 80 almost a month now.

Took about 8 and 1/2 days game play but using specialist gives way more XP also only play FFA.