Agreed with Yaks... Plenty to choose from, but it does kind of depends on what you're after.
I currently own an Aggie Octamizer (main board), MXR Bass Octave Deluxe (moving to second board?) and Ampeg Sub Blaster (second board). In the past, I've had an OC2, OC3, Octabass (Black Label, but not the updated true bypass version), Micro POG and POG2. I know the EHX's aren't really what you might be after... But they still do octave down. Unfortunately, none I've tried or know of in a 1590A besides the Mooer.
The EHX's tracked excellently, but that's really their only redeeming quality, IMO. They're digital (which you said you don't want) and noisy, as all of EHX pedals I've owned have been. I got rid of anything EHX long ago. Mainly included to warn you off, just in case. These are not the droids you're looking for.
The Octamizer (also the older one that DavC mentioned above) is more of a vintage warm/fat octaver, but still has good definition of sound. Good tracking and can get pretty freakin' huge beef. I normally don't need to go over 9:00-10:00 on the octave level knob. The controls are pretty interesting and the way Aguilar designed them allows for a great variety of octave flavors. More on the vintage side than the MXR, but with enough synth vibe to be convincing.
The MXR tracks the best of the bunch I've owned, consistently down to a low F# on the E string. Quite a bit of attitude and growl, particularly with the MID switch engaged. More on the rock side of the scale, but can still pull off some of the synthy-ness of the OC's.
Boss OC2/3... Good octavers, good tracking. Pretty synthy octave flavor which seems to be why people either like them or don't. They weren't quite the flavor I was looking for, a little TOO synthy. I didn't own them at the same time as the MXR and Octamizer, so I didn't get a chance to directly A/B compare.
I owned the Octabass for a long time and it's a great pedal. Again, somewhere in between the MXR and Aggie for a sound, leaning a little more towards the vintage warm side. Consistent sound and good tracking (but not great)... Think of it as the MXR's "well behaved older brother." They supposedly improved the tracking on the updated version.
If you really want vintage warm, track down a Sub Blaster if you can. It doesn't track nearly as good as the newer octavers (it has trouble on anything below an open A), but there's something about the sound that the new pedals just don't have. It's a hefty chunk of a pedal, doesn't sustain all that well and there's a smidge of artifacting, but that's all part of it's charm. Smoothest and warmest octaver I've played, and usually when I'm using an octave pedal, I'm playing up the neck anyway so tracking isn't too much of an issue.
Hope maybe some of my info helped at least a little! The Octamizer and MXR BOD are my favs, and are different enough to warrant keeping both. MXR for my urban gospel band, Aggie for my funk cover band.
5sg.