Have stayed at Marriott Grand on Tverskaya several times. Have not stayed at Marriott Royal/Aurora near Bolshoi. Altthough I have walked past it many times. In terms of location, Royal is a bit closer, but Grand is only maybe 15 minutes walk time differece. Have not stayed at Marriott Tverskaya. I think the rap on Marriott Tverskaya is that is not quite up to snuff compared to the other Marriott properties in Moscow, however, I have had friends stay there and they seemed to be fine with it.
Have not stayed at the Renaissance in St. Petersburg yet. I beleive this is a new property and was recently opened. I may be wrong on this.
I think if it is open, it is the only Marriott property in St.Petersburg. Other quite nice hotels in St.Petersburg are Aurora, Kempinski. Also, the Nevsky Palace is quite nice as is the Radisson SAS.