Agreed on the flux, agreed on the metcal. And oh yes, silver bearing solder is really nice. I only use it for repairs of solder joints that have failed mechanically. If you use it for everything, that solves that problem... but a little rich for my blood.

Hobbyists and technicians get obsessed with cleaning off flux. Hobbyists have no business cleaning flux off boards. It's very easy to wind up freeing corrosive salts from the rosin matrix. Then they smear all over the board to corrode and conduct. My rule of thumb is if you can't measure the cleanliness of your board, don't clean it.