It is a shame that there seems to have been no genuine, independent tests comparing the efficacy of the many zapper models and the blood electrification unit. I only have a zapperplans zapper (due to a severe lack of funds), but plan to purchase a supposedly "better" model in due course...possibly after saving for a Bob Beck unit. I hope others do not take offence, but I find it hard to fully believe the proponents of different devices as each party has clear vested interest in their product of choice (which is completely understandable); thus an independent opinion proves hard to come by.
Perhaps the only real option is for others to test each device individually and then compare results. I certainly shall, as soon as possible, providing I can raise the required money.