Dual-Extruders, are they worth it?

[Bobby Lin]

I agree with the posts above, one of the best advantage of having a dual extruder is that you can switch to another in case the other one will fail. If you really need to use dual extruders in printing then you can buy the printer. I haven't really used dual extruders while I am printing so personally, I am good with just one extruder

[SwitchedMode]

I thank everyone for their input. I realize this may not be the most interesting topic.
I don't really need two-tone prints, although if it's an advantage, sure. Back-up is defiantly a good advantage, yes.
What im interested in is the print quality/detail in using 2x extruders , one extruder having a smaller exit diameter than the other for 'detail'. I need to print things like adapters and couplings to join multiple carbon fiber tubes into 1 node. Also i'm going to attempt to print housings for EDF's (electronic ducted fan), and thrust tubes. These are obviously on a small scale for sUAS, small unmanned system. They won't have any flame component and not much heat either except maybe some radiant heat from large brush-less motors.
Has anyone handled or tested ColorFabb's XT CF20 ? I'm interested to see how well it runs through printers...etc.

[makerparts]

I tired once to add a 2nd extruder to my printer. but I found that levelling was a pain. even with two identical extruders. the hotends would be slightly different lengths. and it was difficult to adjust them to be the same. Perhaps less of an issue with a printer that has this preset but as a DIY option it can be a pain.. BTW once i did get it working. never used it and removed the 2nd head a month later.

[curious aardvark]

There are a a number of printers around at the moment with different sized printing nozzles.

Have a look at the cel robox.
Not the largest print volume. but does have different size nozzles (I think a 0.3 anda 0.6 or 0.8 - for fast infill) and the ability to add different tool heads at a later date. Also not a bad price.