I have a 7" coil version and have several hundred hours on it...found lots of silver and gold jewelry and plenty of coins.
A couple of years ago a very generous member of another forum ordered a new 8" model and sent it to me for a run through first so for 2 weeks I put it through its paces.
It was pretty much the same fantastic tool in just about every area I compared.
The target separation even in heavy trash was superb, recovery was just as fast, the 8" seemed a bit deeper although I never really came across any super deep target except for a few iron pieces.
I still think it beat out my 7" a little and that was a stock setting while mine has the sense turned up internally to almost max. The most important super power in my opinion besides the extreme fun part, and a main reason I believe everyone should own one of these if just for this application, was exactly the same on both units.
That would be the ability to double beep, triple beep on shallow targets, on any metal near, close to or even leaning on large metal like big tot lot iron, fence poles or bench legs.
There is no other detector I own with any coil or combinations of settings I have ever used can find these type of close to other big metal coin sized targets as easily and effortlessly as the Compadre can...and believe me I have tried.
There is only one thing that I did find slightly different between the two, and this was not a deal-breaker by any means, was in the area of discrimination.
I am not sure why but I suspect it might be because of the donut coil, and the small coil model might just work exactly the same as my solid 7" coil model for all I know.
On my Compadre when it comes to zinc cents, not the ones that are eaten away but the ones that are still whole, every one of them disc out or in my case disc in because I always dial past the fade out point and then back down, they all end up with the disc knob in exactly the same place every time which would be dead on 3:00...every blasted one and I have dug thousands.
In this world I take everything with a grain of salt but there are a few things I consider in stone.
The sun will always rise in the east and set in the west, the government will attempt to collect what they believe is their fair share of taxes from me every April and full zincolns will disc in at exactly 3:00 every single time on my Compadre.
There actually might be a hairs difference on that disc knob position but if there is it is so close and such a tiny difference I can't tell.
When I used the 8" coil model I dug lots of zincolns and even though many behaved the same and came in at 3:00 several others came in a bit higher and others a bit lower...not much but enough that these differences I could see and I did notice.
Again not a huge deal and I wouldn't have noticed this at all if I hadn't dug so many of these with mine but I did have that experience so it was noticeable to me.
I can't tell you if this disc stuff would be different on any other target type.
Nickels are weird and come in different all the time for me so I would never consider calibrating that disc knob to that coin, trash and even tabs can and do come in at different places and of course high tone copper cents, dimes, quarters and the other bigger coins don't disc out so I have no data on those.
Zinc cents, however, are something I can consider a good target to calibrate to.
Even my Vaquero, as tight as the disc is on that great unit, is not as exact on zincolns as my Compadre is with a couple coming in a bit higher and lower too then at exactly that 3:00 position with 3 different coils.
My older Compadre is exact every time and I trust this, have confidence in this behavior and I hope it never changes.
Again not an earth shaking difference and it would not stop me from buying and hunting with other Compadres if I ever lost or destroyed mine, but once you get used to something and feel you can instinctual count on it it is hard to get comfortable with something else so I am glad I have the older model.
