I have the press shown above (from Dans) and can tell you that it is much higher quality than home made versions. The Park Tools cup press is great, but doens't work when bearings are already in bottom brackets and it is something like 3 times the price of the one shown.

The cup press has saved me a lot of headache and worry when installing headsets and bottom brackets over the past few years - and after 15 years of hammering them in, I am well aware that it is possible to pound them in, this just makes it a lot easier.

The threads are a little shallower it seems than that which you would find on 1/2" threaded rod from Home Depot, also those aren't just washers, they are floating on bearings so that when you can easily crank down on the nut to press the cups in place without generating a ton of friction against a washer. It is, in my opinion, a definite equivalent to the Park Tools cup press at a fraction of the price and of much higher quality than a generic home made item.

Since I already had a dialed bike, it was a good Christmas gift, but I'm not sure I would buy it myself... I would recommend making a press instead of hammering the cups in. It's what I should have done when I started riding. drrrr

I also never use the spacer inside the cranks as it lets my cranks spin to easily. I hate (HATE!) when my cranks spin on their own, and removing that spacer will generate a little more friction on the cartridge bearings and keep your cranks from moving. Not as friendly to the cartridge bearing, but I haven't broken a cartridge bearing by doing this either.