The Daven six switcher has very good isolation and high max attenuation of 90db. (20x4+10x2)
Its drawbacks are that it is a bit heavy physically large the push buttons don't make it easy to quickly experiment with attenuation, and it's difficult to tell quickly which buttons are down.  The button posts are easily bent.

The texscan rotary attenuator is VERY good.  It has very good isolation, pretty high max attenuation of 70db, the knob turns easily all in increments of 10db, and can be operated very quickly.  Stan says attenuation accuracy on them is extremely good, but that's not too important for foxhunting.  There are no specific disadvantages to it other than to be very careful not to transmit into it since it would be easy to damage and difficult to repair and is valuable.

The weinschel programmable is very accurate and switches quickly with arduino control.  Its relays should be about 30mA each, and have common ground, so would require a positive drive signal at a moderate current, higher than can be directly driven by arduino.

The offset attenuator appears to work very well.  It performs better at 4mhz than at 2.  The output gets noisy when the dial is past the 3 o'clock position.  Attenuation appears to be nearly infinite when fully counter-clockwise, though it may not be linear near the low end.  It actually *amplifies* the signal when attenuation is low (past 3 o'clock?) due to additive mixing

The tecscan 0-1db rotary is too small to be of any use to me.  Stan may be interested in it.

The cheap switchable attenuator has poor quality switches and poor isolation.  I should sell that at a hamfest.

The former 75 ohm toggle looks like it should be good, but has a ceiling of about 55db due to isolation issues.  It may not be useful.

The low daven could have its resistors replaced, perhaps from the 75 ohm toggle, to make it as useful as the other deven.  It will need to have its balancing capacitors removed, so it's not as simple of a job as it may at first appear. (the entire switch mechanism has to come out of it)  It will also need new BNC connections installed like the larger deven had.

The balancing caps on the larger daven have already been removed.

Constructing some audible s-meters should be a high priority at this point.  Realistically speaking, I may never find a good use for the weinschel attenuator, and the texscan may be outclassed by the offset attenuator because the texscan is going to require construction of an rf-tight box for the sniffer radio

I also need to acquire some rf-eliminating feedthroughs.

The additional rotary 70db attenuators have sma connectors but i have a supply of adapters and some crimp connectors.  they appear to also be good quality.