It helps that the latest round of frames to arrive are the wonderful shapeshifting Swobo Crosbies. In stock regalia, the Crosby is a mild mannered, if eccentric, single speed cross rig.
Designed by Sky Yaeger, the Crosby mates some crazy hydroformed 7000 tubes to Paragon-style sliding dropouts and a carbon canti + disc friendly fork. That's a pretty good platform for all sorts of things, but the stock build is... pretty safe, and a jack-of-all-trades that isn't really ideal. I was skeptical at first that the Crosby could be the Jekyll & Hyde chameleon that I've been searching for for the past couple of seasons: a single, lightweight frame that could be easily morphed from a high performance commuter to a cyclocross rig to a passable road bike, and back again. What we've discovered is that not only can the Crosby fill these roles with aplomb, but it's so much more: a dual-disc snow bike! a high BB fixie! a Geekhouse doppelgänger!
The semi-sloping top tube doesn't slope too much to make it difficult to shoulder, and there's a nice comfy flat section exactly where you'd want it. The front end is surprisingly twitchy, but in a good way, allowing for single-track style cornering if that's your wont. The best thing about the sliding dropouts for geared setups is the ability to change your wheelbase, by as much as 2.5cm! This means that in road bike mode, it will feel more or less like a decent aluminum road bike, and in cross bike mode, you'll have a little more stability and cush.
At only $550 for the frameset, Crosbies can be built up for as little as $900 (single speed). A cross-friendly 1x9 setup will run about $1200, and a full Rival kit still only comes in at $1500. I really wish we had these a couple of years ago when an entire crew of ruddy-faced Tatito newbies were racing road and cross on a motley assortment of aluminum cantilever-equipped frames.