When i did my DAS coupla years ago was a they loaned me a 125 whenever one was free (like you i already had CBT) i had use of it for a few hours a day which gave me valuable experiance before jumping on the 500's (also got to know the test route
)
they also gave me the option of following the instructors behind when they were teaching others and generally evesdrop other lessons for tips etc
was with
5 star training if that helps, they were a good laugh, have a relaxed approach to a point and have a high pass rate