Greetings,
I have the Keeley modded BD-2 pedal. I used the non-modified pedal for a while and there is a substantial difference. It keeps the bottom end nice and fat while not sounding like the dreaded 'swarm of bees', which I think most Boss overdrive pedals sound like on bass. I've never heard Analogman's version, but I'm sure it's quality too since I have his DD3 delay modded pedal, which sounds great. I also use a Russian version Big Muff for ripping heads off and a Fulltone Bassdrive for that 'overdriven SVT sound ' - this pedal sounds great going to tape or hardisk. Hope that helps a bit.
Ed Iglewski