I did my initial with AA and a renewal at JAS...
AA are good, you get put under the pump a great deal (which works for some!) and being based at YPPH you get to do a landing off every approach (mostly ILS) great to brush up on your CTA proceedures and lots of gee wiz trucking around all the heavy metal! Their sim is great, based on a Navajo with actual a/c guages and the like, makes you work hard on assymetric IF.
Don't let RM's arm flapping and exasperations when you flub it put you off, you'll be better for it and the other instructors were all good (circa 2001).
I did find JAS more my style however, comprehensive and tailored training to your needs and capabilities (AA's course ran on rails and presumed you had recently done your CPL and were throughly familiar with all the texts re: proceedures, almost military in rote knowledge), if you didn't know something, or were a little rusty they filled in the gaps and made sure you read up on what was required. The do alot more ratings and it shows in their training and application of practical knowledge. The Baron is also a more suitable aircraft (it'll save you the cost of one additional rating) compared to the Duchess as it'll follow that it may well be one of your first types in the charter world.
rN