I have good experience of a 10 day inst program as an instructor. (In fact I think I have done about 6 or 7 of them in my instuctor days). Very tough and VERY tiring! If you can give yourself 14+ days all the better. If it works out 10 days is great but that means good weather (yes even though its Inst training VFR weather speeds up the number of practice approaches etc you can get done), no a/c avail problems, thorough knowledge of the practical aspects before day 1, the knowledge test completed(nothing worse for slowing down a course if not passed, nothing worse than a fail in it during the 10 days for knocking confidence either!) What tended to happen is that one day would get screwed up (always seemed to) and that would lead to a highly stressed day 9 and 10-sometimes with the IFR x-c qualifier being done on the day of the checkride.
Really the 10 program is a sales pitch. If your goal is a career pilot then approach it from the angle that you want to maximise your learning time and give yourself a little longer. Better to take your time and consolidate your knowledge and skills than to just burn out in 10 days for the sake of just a certificate.