Neither of them are horrible. Beware of ET's 757's, some them only have 30 inches seat pitch however ET sells very cheap C-class upgrades at check-in and has very nice employees. MS generally has a nicer, more consistent hard product than ET but MS is also dry airline and has some of the most surly staff I have ever encountered. CAI and ADD are airports of similar quality.

I would try to get on the TP nonstop or even on TK via IST before I would choose either of those carriers.