I have a Flint, which I use for both bass and (shudder

) guitar! I grew up on a steady diet of Chris Squire so tremolo was a key ingredient in lots of his bass lines.
I used to have a 1962 Fender Concert amp which has the "harmonic" vibrato type of tremolo in it; the Flint comes close to that sound (the " '61 harm" setting) but without the thumping caused by DC on the signal in the amp.

I love the sound of both that and the " '63 tube" settings (I used to have an early '70s Princeton Reverb Amp with tube bias tremolo) depending on what I am going for (the one

); the " '65 photo" setting is a bit too choppy sounding, and nothing like a real opto tremolo sound (I had a 1966 BandMaster with a great sounding opto tremolo in it). There is one setting of the " '65 photo" that is kind of cool though, with the longest speed and highest intensity setting of the controls.
As to the reverbs, I do use it on both bass and guitar. I am not a fan of the " '60s" spring reverb sound, way to artificial for me (again the Princeton Reverb Amp, and also my Swart STR-Tremolo - fantastic tube bias tremolo on it - are my references). It does work okay for certain things when set at a fairly low intensity with the Decay control set high. However, both the " '70s" and " '80" setting are amazing to use in all kinds of ways, too many to mention here, you'll just have to watch the various demo vids out there, or better yet, get your own Flint.
Lots of people think the Flint is too expensive, but I see it is as two separate pedals in one case so the price is just fine, IMO.
The two effects can be switch around as to which come first in the chain which provides for some different sounds as desired.
The stereo input is useful to use the Flint as a Rick-O-Sound® box, just run a TRS>TRS cable from the ROS output on the bass to the Flint and use the left and right outputs of the Flint, and there you go! The tremolo remains mono but the stereo reverbs are amazingly lush.