I really can't comment on the GAP Pre73. But I do have a lot of experience with the Hamptone HJFP2 (as well as the HVTP2) and I am also familiar with the HJFP1. The HJFP2s power supply is very hefty, has plenty of reserve and should last for a long long time. Also being that the power supply is integrated inside the enclosure with the rest of the preamp circuitry has its advantages (you don't have to worry about keeping up with external power supplies, wall warts etc.).. Scott has the grounds worked out and the power supply is extremely well shielded. Hence the HJFP2 has an extremely low noise floor. The kits are very well thought out and the parts quality is top notch. The HJFP2 can be very clean and pristine at lower gain settings and can be a beast at higher gain settings with some really cool harmonic color (distortion). The enclosure that comes with the kit is indestructible. I am very certain the parts quality is much better in the Hamptone pres vs. the GAP Pre73. Don't get me wrong, the Pre73 is a great buy and for what I understand a fine sounding pre. I just don't know if it will be with you 15-20 yrs. down the road as compared to the Hamptone. Being that the circuit design of the GAP pre73 is closely based on the Neve design I would expect the sound of it to be more Neveish than the Hamptone. You say your band is
more vintage art rock....the Hamptone would work very well for you IMHO.