I've used both the Bass Max and the Underwood. The Bass Max sounds bottom heavy but good (the "Sometime Ago" clip on my site was recorded live using a modified Bass Max many years ago), while the Underwood tends to sound brighter and more detailed. Based on your situation, I'd probably go with the Underwood because it's thinner than the Bass Max, meaning that it's more likely to fit in a normal bridge and/or will fit with a shim. The Bass Max, which is a good deal thicker, will often require filing/shaving of the bridge wing in order to fit.
Good luck, either way.
Thanks for the warning on the width of the Bass Max, I didn't know it would be that thick. I'll look more into the Underwood, it looks like Lemur has some good prices on that right now.
The BassMax is thicker than the underwood and the Planet Wing. I have used the Bass Max on quite a few rental/borrowed basses. If the bass has not previously been fitted with a wing pickup it will almost certainly need to be shaved/sanded down to fit. I bring a fingernail file (the kind with sandpaper on a stiff foam backing) with me to file out the wing slot to fit. I hate having to do covert lutherie!Also I have run across some bridges where the wing comes to a point and doesn't fit the pickup well at all.
I forgot about oddly shaped bridges - and who knows what I'll run into. I'd like to avoid taking a shop's bass under the knife as much as possible.
Well, it looks like its between the Barcus Berry and the Underwood right now.
Thanks so much guys!
Also I have run across some bridges where the wing comes to a point and doesn't fit the pickup well at all.