TC, I was surprised after reading all the posted answers to your question that not one reply mentioned the 8" concentric (donut) coil as a potential coil choice. This is an extremely stable coil, and gives excellent target separation, which is why it was the standard coil that Tesoro used to put on many of their older machines as the primary coil. I have found this coil to be very good on the Tesoro sabre detectors, and also the Vaquero too. For heavy trash, this coil will work well and can provide some good depth capabilities - so that's why I have always touted this coil to others who ask.
Personally, I find that it is very lightweight and delivers excellent target separation (just like the 5.75" coil does) but can deliver at least 1-2 inches more in depth on coins, even though the little coil does give quite respectable depth, for its size. I'm not really familiar with the cleansweep series or elliptical coils particularly, but from what I have read, the ellpticals are more suited toward hunting in areas with heavy target density (e.g. trashy parks) - but are not really used for their depth capacity, per say. Many have said that Cleansweep coils tend to be perform better in areas with less targets, more for deep coin hunting in older well-worked parks, schools, yards, or possibly also for dry sand beach hunting. So, I guess you should evaluate what coil to pick based on the type of hunting you tend to do most often.
Thanks,
Mark