Not having flown for a long time, had to do a full ATPL/IR flight test in South Africa earlier this year. Although I had plenty of glass experience I decided to do the training and test on a Twin Commanche rather that a Twin Star and am glad I did. It would have taken longer to get used to a different glass setup than it did to go back to an analogue.
However, if you are training up for a professional licence, you are presumably looking at an airline simulator check somewhere either quite soon or down the line. I don't know what most airlines use as sims these days for checks, analogue or glass, but I think that if I had that particular decision to make, between the two cockpit systems, I would tend to be more motivated by what a likely airline company was going to stick me in to for their assessment ride.
I suspect that it is as difficult, having trained on one system to adapt to the other, although the analogue will always, to some extent, stay with us because of the basic training. Also suspect that in Europe, most sim checks will be done in either a full glass cockpit or a mixed one, where some glass experience would be useful.
If the pass rate is higher in the Twin Star then surely the dice are loaded in its favour over something like a Seneca? I do remember as well, from SA, that a lot of system knowledge had to be absorbed for the Twin Star. It is a very different aircraft than that on which anyone may have done their basic training but as has been pointed out, much of this transitional difficulty can be resolved by pre training flight book work and back seating, which is an invaluable aid.
Of course, another point to watch out for in all of this expensive decision making is how long Twin Stars will still be in operation, given the company's present financial difficulties.
