Once you've been through initial and have taken the type ride, recurrent training (for Part 91 operators) is "to proficiency" and the annual proficiency check is normally done "progressively" - meaning that the instructor/PPE simply checks off the boxes as you successfully demonstrate each maneuver during the training. The training for Part 135 and many Part 121 crews is different - you train to a specific syllabus then you take a sim check. I've been on the receiving end of both types of programs and the "train to proficiency / progressive check" seems to provide, point for point, the most training coupled with the best overall results. I understand that the FAA is allowing some 121 operaters the leeway to do what 91 operators have been doing for decades.
When I first started flying the airplane I currently fly, it was on a 135 certificate and we had to jumb through all of the hoops to get up and running on the certificate. I had an initial and something like 16 recurrents under my belt at the time. I didn't expect to have any problems at the check ride and I didn't, but I was really annoyed at the "process". It boiled down to this - the 135 guys follw a very specific training program and get what amounts to 2 days of practice in order to prepare for the checkride on the 3rd day. Part 91 guys get 3 days of training. The pilot proficiency check is done progressively. The bottom line is that dollar for dollar, there is absolutely no comparison between the training for 135 and 91 at the same school.
"Pure" 91 operators are only required to attend recurrent training annually, however, I know of few crews that "train to the minimums". The majority of crews attend recurrent on a 6-month interval. For the most part, operators of corporate jets train with one of two providers - FlightSafety or Simuflight. Both companies provide top notch training. (In fact, many airlines contract with FlightSafety to provide their training.) In addition to the specific aircraft systems and simulator recurrent training that we get, we also got company paid periodic training on many other things such as first aid and CPR, high altitude physiology and altitude chamber visits, weather radar courses, aerobatics and extreme unusual attitude recovery training, survival training, open water ditching, and international operations... The list goes on and on. Granted, the commercial operators are now being required to take some of these courses as well, but Corporate flight departments are typically not considered "profit centers" and typically there is a little more latitude for the consideration of advanced training. This is opposed to many (but not all) 121 and 135 operators where the training goal becomes one of complying with the various minimum requirements of the FAR's. Once that is done then it's off to the line.
Oh well, I'm so glad we got the airplane out of 135, I was beginning to get rusty.
'Sled