Two things:
1) The engine they are proposing is only a 235hp, granted this will produce more than the IO540 over 6500' but I feel it needs to be at least a 250hp if not a 300.
2) The engine is certified to 12,500' only. This is a starting issue as the turbo would not be producing any compression to enable the squeeze bang engine to fire up.
Until these two issues are fixed I'll stick with the IO540.
NAP