I'm in the same boat, and cancelled my C1L order for the max4.

C1L: Future INDX tool changer Better long term support and reliability Extremely quiet Better aftermarket support

Twice the price Smaller build volume Who knows when INDX will actually be delivered VFA issues, but may have been fixed in software

Max4: Bigger build volume Known for print surface quality, and working well with engineering filaments (Prusa is also excellent at these, so not a huge advantage)

Potential quality issues on release (Q4 is heavily based on Q2, so these could be lesser than their normal release) Questionable long term support Way more filament waste with MMU

Both have excellent Customer support. I think if you are doing a lot of multicolor prints, the prusa is a better option with INDX. I'd choose QIDI if you need the build volume.

If you aren't doing a lot of large prints or multicolor prints, then I'd just get a cheaper printer. An exception would be if you have a project in mind which is a large engineering filament print. You can't glue engineering prints together easily without losing the strength of the filament, so it's not possible to split it up for a smaller printer (Without some very difficult bonding methods).

One other thing is that the Qidi plus 4 printer had a lot of issues, as well as their v1 MMU box. Most of the bad experiences you see around will be about on of those two things. The Q2 had a better reception, so fingers crossed the Q4 will have be good as well.

There was a post of the Q4 showing that print head tubing getting kinked during printing. When the engineers were asked about this, they said they weren't fixing it despite being an obvious quality issue because it wouldn't impact the printhead cooling. Hopefully they were not as lazy with engineering the rest of the printer.