I've ridden the Shim a few times. I would buy the small Broadcast over the Shim any day. The Shim's tail is to wide and it makes it unresponsive rail to rail, and it also makes it hard to hold the rail in the wave. The Broadcast is actually Hyperlite's best board. I can hit 360 shuvs and surface 360s almost every time on one. They are heavy and slow which makes airs hard, but the shape is actually ok.
Noah Flegel (Keenan's brother) rides for Hyperlite now and he rides the Broadcast in comps rather than the Shim.
The Broadcast is also he best beginner board out there (at ~$350) besides the Inland Surfer Tako.
Pass on the Shim