Have an Npro- Was my first, it runs reliably but does not provide enough hit. Bought an 801- Provides the hit, but only for a couple puffs. The cart does not seem to be able to keep up with the atty. Just got my 510 thinking "This is THE ONE".- Nope, same problem as the 801. I have tried the coffee straw mod without success. Only thing that seems to work for me is dripping straight onto the atty. Problem is that I drive a truck for a living and I don't want to get in trouble with MADD (MutherF'r's Against Dripping and Driving). Seriously, does anyone really want me out there behind the wheel of an 80,000 lb truck trying to drip. I can do it, but it's not ideal. Please help!