I don't use a Helix, but an older HD500x as my pre-amp as well as effects. It is certainly more limited in respect of bass specific bass amp/cab sims, but it's still incredibly usable, and sounds great.
I would say that it does give you the ability to have a multitude of different variations on amp & cab sounds, useful for different songs, add in effects, and you can switch between effects and/or patches during songs / between songs etc. The only other comparable pre-amp that could do something similar would be either the SanaAmp BDDI Deluxe, or the VT Bass Deluxe (both of which are now discontinued).
A single pre-amp pedal would mean that you keep a "core" sound, and add additional effects to that. To vary your sound, you'd need to add another pre-amp or something like an EQ pedal.
Maybe take a look at the Helix LT, which would give you more connectivity options as well as switching options.