If your still running those mixed rollers to give 6g then you prob want to think of ordering a full set of 6g's then? The lighter rollers will wear down quicker than the heavier ones. Mixing up is really just for testing out to find your ideal weight, once you get it then its best to replace with a set of that weight.
Did you try a stiffer torque spring? 1000 or 1500 rpm? If it feels like you could use better power up hills thats a cheap mod.
If you were to fit a race variator, oh i dont know........maybe a Malossi Multivar
, you may even enjoy it even more?
..................just sayin................. that' be my next mod ..............
Good thing with scoots is its all pretty cheap and quick to try and if you dont like it you can always put it back.