I prefer beat. it's cheaper and very gas saver. I think ang average fuel consumption sa beat is 1:45 l/km. Ang mio kay 1:30 man sguro to, I had a mio before. When it comes to speed considering all stock, I think beat also has the edge, it's more powerful and responsive sa start and mid end torque. Taas pod ug top speed ang beat. When it comes to after market upgrades, all hands down ko sa MIO kay pwede pa gani mahimo 200cc ang makina. In the end, it's up to the rider whichever his priorities are. Gas, price, speed, after market and etc.
Lastly, consider your weight. I had a mio before then sige sakit ako lower back bone taga uli gikan work kay gahi kau ug untol ang Mio Amore, the reason? I weight 200lbs hehehehe. So I opted na lang XRM kay nindot ug ride and wala na sakit ako luyo. No Im not selling XRM I'm just sharing my experience.
peace!