ORIGINAL: 1QwkSport2.5r
I just don't see the need to use LiPo or to get carried away with a glow driver. If you're killing a NiMH or NiCd in a few hours or within one day, something's wrong.
With the NiMh and NiCd batteries the problem is that they need to be fully charged, you can't just charge it one week and then use it another week. That's where the Lipo has its strength. Charge it once and use it for several weekends, with several weeks in between, you'll always get the a full 1.5V over plug until the battery is fully discharged (since the output is regulated). This means that you'll have that extra boost to start even a slightly too much primed engine on a cold day. Take a look at any of the discharge curves for the NiMh batteries and you'll see the problem, you never get 1.5V and the voltage drops quite quickly with the discharge (starting from fully charged).
As for the bulkiness, yes it is a little larger but the weight is about the same. For those that are a little fed up with the low shelf-life of the NiMh battery-charge and their lower voltage, then the Lipo ones are worth a try, that's all.
The performance of the 1.5V dry-cell batteries are also good, I just can't find them locally anymore.