Thoughts on 5+ channel interfaces for synths?

Been looking to upgrade from my Scarlett 2i2. I have about 5 synths and one mic that take turns being plugged into the two inputs, so I'm looking for an interface that I can route all of those synths into and not have to waste time plugging them in. I'm looking at:

M-Audio M Track 8 (seems solid)

ART TubeMix5 (sucker for the look, not sure it covers everything i need)

Scarlett 8i6 (lil' step up, seems solid)

Tascam 16x8 (not a fan of all the xlr inputs, i only really need one + 7 line inputs for the synths)

Could anyone give me their thoughts on these interfaces? Ideally, I would splash out on a Scarlett 18i20, but they're out of stock right now and it's a much pricier option.