Hey, that's me! I did have Bosco Bullmoose bars on my Quickbeam for about a year, and yes, it did feel very short, although the setback seatpost helped. They later got switched out for Albatrosses and eventually, Avenir Circa handlebars. The QB definitely has a comparatively short top tube; even with the less swept-back Alba's and Circas, I still ride an 130mm stem. I'm still constantly fiddling with that bike but this is pretty close to the current setup:
https://flic.kr/p/Ett4rD
Around the same time I took the Bosco's off the Quickbeam I put a pair of standard Aluminum Bosco's on my Surly LHT, which has a ~2cm longer top tube than my QB (62 vs. 60, both are 64cm frames), and that felt great with a stem in the 110-120mm range. I rode that setup all over for almost two years, including touring from SF to LA. Here it is:
However, I just came in from the garage, where I was working on that bike's latest transformation. Being the fickle guy that I am, it's getting drops (shock! horror!), but only because I have a 59cm Clem frame also waiting in the garage to get built up as a (slightly more offroady) upright all-rounder, and the Trucker is morphing into more of a go-faster bike.