Hi,
there are several showrooms:-
1. the Mall (bland attitude)
2. the Centre (best showroom)
3. Al Nasr (crappy telephone attitude and not interested in giving directions - assumes that everyone who is in Doha has been here for several years and knows exactly what restaurant is opposite the branch)
4. Msherib branch is closed and has shifted just next to the QP offices (very difficult to get parking here though if you are not familiar with the little lanes) - that said this would be the second best showroom. Think the area is known as Al Hitmi.

HtH.