I was wondering if the SRB's are working right for me. A Mark I with a Thumper underneath is giving me 3,447 dV in vac and 3,171 in atmosphere. Trying to get that much dV from liquid fuel sources creates a rocket much, much heavier. It seems like liquid fuel boosters would never be used if this was the case. I have useRealisticMass set to false and when true the SRB's still seem to have enormous dV. Thanks for the mod, it is really fun.