Like bear I have also had (up to 5 coonans) many coonans. Actually, I think bear and I have swapped coonans before! I still have 2 now, 1 compensated.
I have also owned a DE in 357, 44 and 50 AE. If you think the Coonan will be too large for a proper grip, you might as well give up on the DE. I also find the price, way to high incomparision. $188 for a DE vs. $1200 for a coonan.
The Coonan is extremely well made, it takes a beating from the 357 and keeps ticking. I also own a Delta in 10 mm. While they are in the same league for performance, the fireball out of Coonan is sweet. It's extremely accurate and the ammo needs to be FMJ or copper coated to ensure proper feeding. It is a hand full (I have medium hands) and only takes 8/7 rounds. Used stainless models sell from $1000 to 1300, depending on options, if you can find one.
I would vote that it's effectively a 1911 pattern. Parts, stripping and operation being considered.
The new Coonans have been something like 5 years in the making, and if you have the cash, it might be nice to add one to your collection. However, the stainless models have proved themselves over the long run. Not sure how well the new ones are made, yet. Probably the same issue will exist for the new model as the old model, the mags are the heart of the system and currently cost about $100 to $125 US each!
If you could only have a 10mm or the 357, I would suggest the 10mm. Smaller grip is the only reason why. If your heart is set on the Coonan, I would try to buy a used stainless model vs. the new steel version. I personally find the strength and corrosion factor (and looks) to be of value, you may not.
The Coonan is in the top centre, above the colt delta.