I was a member at Popham for quite a few years, and have known most of the instructors at Airborne at some level. I've also flown with several pilots who have trained there, since I'm the "checkout pilot" in a microlight syndicate at a nearby airfield.
Without doubt, the place is there to make money - which probably explains why it's actually stayed in business for so long. On the other hand, they appear to be scrupulously honest about what you need to pay, how long you need to train for, and what the aeroplanes are like - which is pretty good.
On the whole, I'd have no reservations about recommending anybody wanting to learn to fly 3-axis microlights goes to Airborne. I think you'd be well taught, at a friendly airfield, in good aeroplanes. Similarly, I think that you could do worse than flying there for the next few years in one of their syndicates whilst you build up confidence and experience.
So, I'd give them a thumbs up.
G
N.B. If you are just after cheap microlight flying in that area, you might do worse than try Chilbolton Flying club a few miles away.