All great points but as i said they all work respectively. The smaller the coil the less depth and coverage but better separation and vis versa.
Going back to the wrench analogy a big adjustable wrench will also work on small nuts and bolts, work stronger without as much effort but won’t do well in tight spots.
The main thing of the different coil sizes is to be the most efficient for the area you are hunting based on your needs and and technique.
Its great they have more options, the more the better, because one size does not fit all and doesn’t mean it’s useless.
What works best for one person might be different for someone else.Otherwise there would only be one model detector with only one coil size.
Heck id still be happy with a beep and dig detector lol why have all those different features. Id still rather see a company offer many different options you never know when you might want or need it.
Now i did notice with the lg24 especially in the front part of the coil it is more sensitive to targets in a broader area (more coverage for sure) but also definitely more prone to picking up multiple targets close together. Jmo in more trashy areas increase the recovery speed, lose some depth or use the lg15 and lose some coverage.
Personally it all depends on how big of an area i am hunting. In a very small area if you have the time and patience use the lg15 and thoroughly scan the area. Tot lots , picnic tables, definitely around fences, etc. then pop on the lg24 going into more open spaces and the even bigger coil for even more open spaces.
You can actually be the most efficient using all of them, depending how much effort you want to put in