I have 6x of these, all customised to sound great, and they are indispensable to me.

I don't use them to learn at all, but to quickly dial up all the neck notes in a scale or chord to compose with.

Instead of using loops or software guitar recreations I play real guitars into my tracks. It dose help if you have leant playing techniques, which are all easy when you have unlimited attempts to record into your DAW with.

As a learning system, well I'd only get one is it was used.

Hope that helps a little.