I love my Speed Graphic (4x5) and Graphic View II (same format), and the negatives they produce. Even though I haven't made a darkroom print in years, I'd be pretty unsatisfied if the option didn't exist to do so -- in my case, I have an Omega D2 with a Chromega 4x5 color head on it and a spare condenser head I can swap in when ultimate sharpness is needed. If I can ever afford an 8x10, contact printing will be the only way, though; no way I could get an 8x10 into my darkroom even if there was any chance of affording one (maybe if I built it in place...).
As for getting three answers to a yes or no question, welcome to Photrio! That's how it works here.
FWIW, some 4x5 enlargers aren't much bigger than a 6x9; my D2 with the Zone VI cold light head it had when I got it fit pretty well in a temporary darkroom setup in my larger bathroom -- baseboard on a kitchen cart between toilet and bathtub, developing trays on a board over the double sink and wash tray in the bathtub. A D2 has a fairly compact base board (20x20 inches, as I recall) and the cold light head I had actually sat down into a stripped-out condenser housing -- 16x20 from 4x5 with a 135 mm lens had the top of the cold light the same height as the column.
So, I'd say don't let your enlarger keep you from buying into 4x5 camera equipment. A 1 liter Paterson will develop 4x5, up four or six sheets with the right adapter, and 4x5 printed to 8x10 is incredible after you've been working in even 6x6; so much more detail! And you might just stumble into a screamer of a deal on a D series enlarger and realize it'll fit where your 606 stands.