The 'real thing' like a dedicated digital reverb box? Or the 'real thing' like a plate reverb? Or spring reverb? A reverb chamber? Or... heaven forfend... actually tracking in a physical space with a reverberant ambience?
When it comes to creating sounds nearly everything is worth trying at least once. I mean, unless it costs millions in hours or cash and even then...
Hooking up outboard gear you already own? 15 minutes of your time for a sonic experiment? Why not!!!!!!
Sorry I mean substituting a mixer with built-in effects for a hardware box like a PCM 80 or 90.
The built in verb is supposed to use the same chip as in the MX-400 which is not a PCM-90, but is not a bad verb, either. One thing to keep in mind is that one dedicated reverb unit like a PCM-90 costs as much as your whole mixer including the built in FX. You don't always get what you pay for but quite often you do.
Give it a try but see if you can A/B with some other options, be they a hardware verb or a high-end reverb plug-in.