Vacuum brewing is awesome, but it needn't be that expensive. The Bodum models are like $80, and there are a few that are like $20 (but use a disposable filter, which you can actually replace with a glass rod filter from an older model that is no longer made, just check eBay). Done properly it completely eliminates the bitterness of over/under brewing. I know exactly zero people who drink black coffee normally, but everyone will drink my vacuum brewed stuff black. Grind size is really important though, you need to get a burr grinder so all the grounds are the same size if you want to do it and grind at home.
I'll actually post the chart in Modernist Cuisine when I get a chance, it is really informative about what makes coffee good (and not good).
