How could Enochian and Solomonic magick be compared?
I am Generalising here but Solomonic Magick is usualy concerned with the proccurement of Abilities , Wealth , Knowledge and Material Gain. Some can Argue that its Incorrect and treat the Goetia like Demi-Gods thats more demonolatry in my opinion. I suggest reading the Lesser Key.
Enochian uses Calls/Watchtowers/ Aethers and is yes more intellectual and "Technical" and requires a little more experience from the practitioner. Most I would say use it as a kind of pathworking or Vision quest kind of experience but I have knowledge of practitioners using it for more practical methods with success.
Why do people choose one over the other?
I think you have to decide what you are called to or what feels right. But most of the practitioners that I am in contact have experience in both systems.
Are they both quite versatile once you have learned the basics or do they both only prepare you to work with either angels or demons?
They are both versatile but do both take serious dedication to work correctly. And Angel and Demon are both Judeo/Xtian constructs a far to simple generalisation for angel = good and demon = evil. Do you recall who the angel was that killed the first born of egypt?
Could you learn one and then learn the other or would you never mix them at all?
You can learn both but I would suggest getting mastery in one before trying to mix anything up. You are just going to land up not acheiving anything.
I can see that since this board is dedicated to Enochian mainly that I may not get a wide range of replies but starting points would be helpful for me.
We have experienced practitioners in both diciplines feel free to ask questions.