The juice consumption isn't that dramatic. I'd say 10-15% more.
Also, I get MUCH more satisfaction out of the 510 and find myself using it a lot less than my Evo and pen (and less than the 901 I'm testing now)...I actually got over 5 hours out of a 510 battery today because I just wasn't using it that much and I was totally satisfied...no cravings, at all.
So, yes; they use more juice but it seems that cost comes with the benefit of less use and more satisfaction.
Also, I get MUCH more satisfaction out of the 510 and find myself using it a lot less than my Evo and pen (and less than the 901 I'm testing now)...I actually got over 5 hours out of a 510 battery today because I just wasn't using it that much and I was totally satisfied...no cravings, at all.
So, yes; they use more juice but it seems that cost comes with the benefit of less use and more satisfaction.