Cross bolted is better, but it depends on what the intended use is. If you are going for a hot street engine that will never see anything over 6200 rpm, the money spent on cross bolt caps, machining and extra hardware could be moved over to stabilizing the valve train with end supports for the rocker shafts.

Besides, Dave Shoe over on the Network54 FE forum has an interesting project in the works right now that may be a cost effective way to get improved main cap stability without having to go search for expensive and semi-rare cross bolt main caps.