John Smith mentioned the Microvert antenna, which I know
very well.
I made an extensive comparison of the RoomCap (hb9abx)
against Microvert, and was using the best Microvert available
(MV-500) for 40m.
Test at same location, both antennas at same height in
A-B configaration.
Test was performed by many rapid changes between the
two antennas, and the remote station was observing
the signal strength.
Result was, that the RoomCap was 2 s-points stronger
in average, in receiption as well as in transmission.
Rember that 2 s-points correspond to 12 dB.
A very clear result.
73s
Felix HB9ABX