I did both my driving and my pilot's licenses in intensive courses (one week in Burton upon Trent and three and a half weeks in Welshpool respectively) and recommend it. You don't have the loss of skills between lessons that you do with spreading it out.
However in both cases I realise now that I emerged from the process qualified but with a lot to learn. That would have happened, I suspect, from the usual method too, but I don't know because I haven't tried it...
FWIW I didn't learn much of the written stuff before the start of the course. But: I learn quickly; I worked solidly 8-5 every day for those 3.5 weeks, plus evening written work (when I wasn't flying I was working - about 3 hours of flying and 3 hours of working every day, allowing for ground briefings &c); and I am one of nature's exam candidates (under pressure I remember stuff, rather than forgetting it). Plus I have A level maths (a while ago) and was 30 at the time, rather younger than the average, it seems!
Tim