The wording on the visa now reads '....multi entry visa, valid for a stay of no more then 90 days per period, of 180 days duration....begins on the date of entry into Turkey. Not valid for work.
The way I read this is that you can leave and return as often as you like in 180 days but you must limit each visit to less then 90 days. Reads like good news to me!
Residency, although expensive gives other benefits : Driving license (no age limit and has so far proved immune to UK fines!), Telecom telephone, Turk ID number so that you can use the hospital paying only a small fee.