Jeff is absolutely right, the best way to do the flight section of your FAA ATP is during your recurrent. The schools (in the US of course!) are well set up for this and it's a hard but fair check-ride.
Undoubtedly the best way to do the FAA writtens (if you can), is to go over to the US a few days before your recurrent, leave the FAA book behind (unless you have difficulty sleeping on the flight!) and report to ATP
ATP Flight School: ATP Written Prep & Exam (they have about 20 centres in the US to choose from.
You report at 0800 (no beer the night before - seriously!) and sit in front of a computer for about 8 hours (come and go as you please) and when you're ready (or suicidal!) you take the test online. Those of you that know me know that I hate bookwork but this "Computer Session From Hell" got me 90% (first time), and my "swot" buddy 95%!! You don't fail, you just keep taking the test until you pass apparently.
We were given our pass slips and 5 days later after recurrent check-ride......... "I are a full FAA ATP". I could strap on an FAA or M reg aircraft that afternoon if necessary. As Jeff says....."Welcome to the common sense system".
I'll leave you to draw your own conclusions about my In Depth Knowledge of the FAA rules, regs, and systems!! The serious question is, how much do you (honestly) know about the JAA system after the endless, out of date, mostly irelevant, and stratospherically expensive JAA "Exam Frenzy" anyway?
I'm off to the bunker now, expecting "incoming"!!!!
Jez