Also remember that guaranteed rental generally means that you pay for the rental up front and then they give it back to you!! (i.e. included in the price that you pay for the apartment).
By the way, I picked this off a bulgaria forum which shows that not everybody thinks it's over developed:
I've been Snowboarding all over the world for the last 10 years or so. I've also been to Borovets,Pamporova and Bansko. Borovets is ugly, has mediocre runs,very little off piste,but a good feel to the place. Pamporova is a beautiful looking place, but hardly any runs-if you are an intermediate or more, cetainly not enough to keep you occupied. Bansko has the best points of all the other Bulgarian resorts- pretty, adequate runs,plenty of off piste-it is much bigger than the other resorts- and overdeveloped- NO WAY- Bansko is a big town, and has the room to deal with it- this could be an awesome resort- the more popular it becomes and with 2007 and possible Olympics in 2014, the future looks rosy- Value for money, good snowboarding, lovely people- I much prefer it too France, Andorra, Livivgno.
My opinion i know, but i have been to countless other resorts.