I have not. Can honestly say I've never used any of this stuff in my rig. I have tried to SEM DS-1 at a guitar show years ago and a few of his own pedals, like the Java Boost and Compressor. That's all the experience I have with Keeley.
I bloody love that Java Boost . . . it works for me !
OD3 is real sleeper/under-rated pedal
I think part of the problem with this pedal is that it's more than 2X the cost of a SD-1 new and they both say overdrive, so most people think "I can have the super version for less than 1/2 the cost of the regular". But, they are 2 very different pedals, so maybe the OD-3 should be the "Ultra Deluxe Overdrive" or something.
Yes, they are. The circuit of the SD-1 and the original OD-1 are quite similar. The addition of the tone control changed which out of the opamp is used for the signal and a few parts differences but overall, pretty simple circuit. I've modded the SD-1 to OD-1 specs before (at least the 8-pin chip version, not the original 14-pin chip version). The OD-3 is a completely different beast. I opened mine up and it is through-hole components and I did see a couple 1N4001's in there as clippers. Good stuff. Those are great clipping diodes. More headroom and a warmer clip, more natural sounding.
"Stunning Overdrive"
The OD-3 is like neither of them, it's closer to the BD-2 than the SD or OD-1.