A higher mAh battery certainly wouldn't need to be recharged as often, but it won't help with that "nasty filler taste" and the frequent topping off.
For the battery recharging issue:
A 280 mAh Mega battery is a
slight improvement over the 510 battery's 180 mAh. I would leapfrog over that to the eGO/Riva/Hello 016 or a mod. The eGO is 650 mAh, the
Riva 750 mAh, and the
Hello 016 is
1300 mAh. They are all fatter than the basic 510, but shorter than the 510 with Mega battery.
3.7V mods range from 900 mAh (the 14500 battery) to 2600+ mAh (the 18650 battery). [I've never seen the point of mods using the 320 mAh 10440 battery, but they
are popular.] For more about mods, see ViZi's
eCigarette Mods Database.
For the nasty filler taste of the cartridge issue, you can:
- Modify the cartridge filler as outlined by Hellen A. Handbasket.
- Use 510 cartomizers.
- Forget carts and drip (directly on the atty).
If you enjoy fiddling with your e-cig, the first option might be fun for you, but, for me, it's a pain in the ..... I haven't used carts since shortly after I began vaping. I usually drip (it's analogous to lighting up an analog cigarette). Or when that is not convenient (e.g., when driving), cartomizers work well.