I would agree that depth would be all you are giving up, but not much.
What you gain is more important imo.
I find the 12" nf a quieter coil, which means you might hear signals that were covered up by the 14".
I have found some really good gold with the 12" including a 5.3 oz nugget and a 64 gram nugget, but the deepest one was 11 grams, and it was a whisper at the top which I often wondered if I would have got it with the 14".
Have also found some surprisingly small gold at depth with it as well. I have the 17x 13 nf as well, and so far it has been good, but not as quiet as the 12". Nothing really big as yet with it, 7grams is the best so far, but it does cover a lot of ground.
What you gain is more important imo.
I find the 12" nf a quieter coil, which means you might hear signals that were covered up by the 14".
I have found some really good gold with the 12" including a 5.3 oz nugget and a 64 gram nugget, but the deepest one was 11 grams, and it was a whisper at the top which I often wondered if I would have got it with the 14".
Have also found some surprisingly small gold at depth with it as well. I have the 17x 13 nf as well, and so far it has been good, but not as quiet as the 12". Nothing really big as yet with it, 7grams is the best so far, but it does cover a lot of ground.