What is the plane? If it is showing as a 77W ex-Istanbul then go for it like a shot. These are the Jet Airways brand-new 77W's that they couldn't afford to use so they leased them to TK. J and F are pretty much as good as it gets in terms of seat, certainly as good as Star Alliance gets. (Caveat - not flown them but I have seen the seats at trade shows and you'll see lots of TK feedback on here.)
If it is not a 77W then not necessarily as good a deal ....