I'd like to see a combination of oval and rectangular circuits as the pattern/traffic/ATC dictates. As a Controller at a very busy class G airfield, there is nothing more infuriating than having all your circuit traffic outside the ATZ because the Cessna who was number one when he turned downwind ended up on a three mile final at 65kts with an Arrow, a Robin and a Seneca behind him...it happened last weekend...and it happens regularly! but at the other end of the spectrum, a 'constant-aspect' type cutting up a £300 per hour IR trainer (despite having been told twice "Number two, follow...") causing him to break off his Instrument approach is just as annoying for all concerned. A potential problem with keeping circuits too tight, however, is finding time and space to get departures off. The point I think I'm trying to make is that pilots will encounter a different circuit pattern almost every time they fly...I always seem to.... so they need to be prepared to deal with every eventuality..short apporaches, slow flight and constant aspect approaches should be taught to everyone, early in their careers