Right-o, here's Part II, if you missed Part I - check it out here: https://community.guitartalk.co.za/d/26795-bedroom-guitarist-multifx-vs-amp-pedals-part-i
Next, RTFM. Each manufacturer's multifx is a different beast - knowing how to bypass the unit or what options you have when bypassed (e.g. tuner on w/output muted) is the first thing I want to know from the manual. Also, figuring out if there is a Master EQ section is good to know if you quickly need to dial in/out something to spice up your rig for a venue/rehearsal space. And DO spend some time reading up on the forums with fellow users, I've gotten a lot of tips n tricks from reading up fellow owners tales of woe and success.
Lastly, if you are going to gig the multifx - the tones you carefully sculpted at bedroom volumes will likely not sound great at gig volumes or in the band mix. Likely it'll be a bit fizzy or overly bright when the volume's cranked? You might just need a tweak of eq, back off the gain or (as I have had to do), simplify the patch. If your unit has a master eq section, you'll be a happier camper!
There's always going to a tone debate amp+pedals vs multifx. The gap is ever closing. Circa 2018, at bedroom volumes, multifx are hard to beat. Kemper's sound great and that Boss Katana 50w is mind blowing at the price.
For the bedroom guitarist - my multifx for the $...It would be a amp! (facepalm). The Boss Katana 50 (or 100 if budget allows). At 200USD, the 50W humbles the competition and is just loud enough to hang with a drummer. And if quiet is your thing, it scales down to a bedroom friendly 0.25w. All it lacks is a *&ing looper and tuner. . Unfortunately the optional pedalboard on the 50W is a bit rudimentary, can only change between 4 presets. Though the 100W has a pretty decent one which is more pedalboard style.
My second choice (budget/size) would be a POD x3 bean. It has all the sounds/functionality of the POD x3 live in a tiny thing that can run off batteries. Work well with literally any instrument you choose - acoustic, electric, bass, violin - swiss army kife style. Add a floorboard + stand and it'll gig. One downside, I don't see them all that often 2nd hand though...and still no *(&-&21! looper.
I'd think about the zoom g1on too, it's cheap and has a looper, tuner and a drum machine (winning!). Though I'd probably get the POD x3 for guitar rather. Line6 does pretty decent gain tones and having two signal chains to blend is VERY useful - something I really miss in other products.
For the bedroom bassist - I'm leaning towards the zoom b1on/Zoom B3. The b1on is R1200 w/o psu. Comes with a drum machine AND a 40s looper. Someone was listening!
If you were gonna gig some bass, the choices widen out. TC Electronics BG series w/toneprints is the katana style option. Pedalboard style, the Zoom B3 or Sanmsamp flyrig are both cool. If all you want is some drive and lots of volume, a fender rumble is still the business.
Boss ME50 - Bombproof like a Boss with old skool pedalboard style usability. Still relevant today!
Sansamp Flyrigs - New school usability. Comes in more variants than ice cream - the bass one looks like fun!
Ibanez Powertrio - Simple, old n cool (but switches are fragile).
You've probably noticed I'm a Boss/Zoom/Line6 fan - these are the products I've used (in anger). Not that others don't work well or are great alternatives. But for my purposes of bedroom entertainment... I've found those to work for me