Both the bikes are good to ride and specially the FZS version 2.0 is highly refined by its last update received. It has got a fuel injection system for better efficiency in terms of performance and mileage. It also comes with wider tyres, making it more comfortable to ride. Power values are more when compared to SZ RR version 2.0. SZ RR and FZS have a very low mileage difference between them, which expands when the throttle of both the bikes are pulled. FZS being a more performance oriented motorcycle comes up with more fuel burning when at high speeds but in general riding, the difference would not be a meaningful point of concern. You should go for FZS version 2.0.

Yamaha FZS Version 2.0 - It's Not A Machine. It's ME.