Hi Brad,
I have both and use them both.. A lot. However I have never done any direct comparisons on located targets so can't tell you "exactly" how they compare just how I feel about them and their general overall characteristics.
The main differnece as I see it is mostly to do with the audio characteristics and concentric vs DD coils. Both are deep and both have there place in my arsenal. the Advantage with the Ts800 coil (actually around 7.25") is great in heavy iron trash and quiet compared to the 1270. The audio tone on good stuff is unmistakeable and it gives a very good initial hit on some pretty tough targets. The other coil I have is the 12.5" Excelerator which gets great depth outdoing the CZ on deeper targets IMO. It handles moderate iron very well. Very deep even in some pretty tough conditions.
The Advantage weakness is the ML coil connector which will not take a lot of strain and the fact that with larger coils it starts to like some iron and really likes bottlecaps, but you learn to compensate.
The 1270 as you know takes some time to get familiar with, especially the audio on the deeper stuff. I find myself removing the top inch or two to get a better read on the weaker responses at the edge of the disc range to see if its ferrous or non-ferrous. The 8" coil hits coins a little deeper than the ML TS800 especially the tilted on edge ones (that is a definite weakness of the smaller DD coils). The 1270 with the 10.5" coil is DEEP! Loves on edge coins and handle moderate iron very well. One thing I really like about the 1270 is its ability to hit mid depth coins very loud even with the coil several inches off the ground. Bottlecaps are generally not a problem unless you are running down close to nail level disc.
They are both good machines and for those hunted out areas where you want to dig it all they both have there place. They are part of my permanent arsenal.
Tom
