I have the electronic subscription for two main reasons:
a) I am a cheapskate and it’s cheaper;
b) I already have far too many chewed trees in each of two houses. Doesn’t stop me collecting more, unfortunately …
I read both JBAA (and similar publications) formats about equally often and likewise in depth. There is something immensely comfortable about having a physical artefact, especially one which is much safer to read when lying in a hot bath or a sauna. That said, the portability and physical storage space of a digital version has a lot going for it.
Horses for courses.