In mid-July 2007 I tried the 5 element VHF Yagi out on the field.
Supporting mast was the lower section of a fiberglass fishing rod ("telescopocket 4"). Antenna performance was good. Beamwidth not much tighter than the 4 el., but I did notice better signals and reports were encouraging.
There's still one goal to reach: use a telescopic fishing rod as boom, but given its conical shape I can make up a good element-to-boom fixing harness.