Was discussing this just the other day. Thinking about experimenting with it first. I'd like to try with Gran Classico and some different vermouths, as I've only used Campari with M&R or Cinzano. The Red Hook is another candidate.
Make sure to request 2:1:1 ratio (rye/bourbon:Campari:sweet vermouth), or at least 1.5:1:1. The common ratio is 1:1:1, but most agree the drink's quality is vastly improved by upping the booze quotient.
V - Think I recall you digging Manhattans or Old Fashions. If you haven't already, you gotta' pair a Boulevardier with a nice cc. I can't stop.... I prefer with rye, but this Four Roses single barrel is money too.