In all honesty, it is a small amp limit. However, if you run a 3 ohm carto at 6v, that is still 12 watts at 2 amps. 2 ohm carto at 5v is 12.5 watts at 2.5 amps..you get the idea..If he is running DCCs, it doesn't actually add up to 20 watts..each coil is at 3 ohms, in parallel the cumulative resistance is rated at 1.5, because the power is split up between two coils. For a DCC the formula is W=V*2/R*2 or R+R. So at 6v, running a 1.5Ohm DCC it's 36/3=12 watts. You can easily achieve that with a VTube (LT). I run tobaccos, coffee, nutty liquids in a 2.5 or 3 ohm carto at anywhere from 5.4-6v and I think it is great. I will throw a fruit/sweet liquid in a 2 ohm carto and run it at anywhere between 3.9-4.5v. So don't let the 2.5 amp limit fool you..even though it is "overly safe" compared to what is out there, if you use it correctly you can still achieve a great vape.