Originally Posted by pogonation

If you are going to be staying that much then the most important thing is that you stay at the most comfortable property with the best staff/service (and location). It may be worth trying a few properties out first to see which one suits you the most.

I would also recommend contacting the hotel managers and explaining your situation to them. 3 weeks every month is a long time and a lot of money for them so see if they can arrange any special perks. One loyalty scheme may appear to give more perks but a competing property may offer more to you directly.