Both NEL and Cors are related coil brands,i use a BIG Nel which is exactly the same coil as the Cors 15x17,big old heavy bruiser of a coil and i use one on my T2,its not a everyday use coil for sure,its ground coverage is its main advantage but mainly for clean open pasture sites that i use mine on,then again it only comes out to play whn i suspect the odds are in my favour of finding something decent.....'its all about the reward to effort ratio' in my mind,if i have found a few scattered coins in a tight radius this then sends up a green flag that a possible a scattered hoard could well be in that location,then these are the times that i would use the 17x15 coil as i the odds are increased in my favour of 'possibly' finding a deep container.
Regarding a few downside when using this or infact any large coil and i do have man many large coils in my arsenal,they are not the best for pinpointing,not all that good infact can be abysmal on small target as they are mainly designed for ground coverage and larger targets,target masking is one of the biggest issues and you can infact miss a decent target if you have a desirable and a non desirable target next to one another.
On paper theses large coils sound like the 'dogs danglies' and will improve your find rate no end,alas that is far from the truth,if you find a immaculate 2nd hand large coil of what ever size at a decent price that the original owner has taken the massive hit on the price then its good i guess to have one in your truck just incase you need one and the finds are beow what a normal detector/coil set can reach,but just to buy what could be a massive white elephant that sits around gathering dust after you have paid the full retail price then that does not make much sense in my mind.
If you have a specific use for it and you think the 'price to use' ratio and also the 'reward to effort' ratio is in your favour then go for it.
