Well, I've remembered to come back and post, so here I am!
The gun held up well. I'd only used it once before down the end of the garden just to ensure it was firing off properly before setting off to Scotland! A 10 hour drive and an extra day later I can happily report that the gun held up very well! I was using a 2400mAh 7.4V LiPo battery that was charged the day before the event and I imagine was nowhere near depleted by the end of the day.
I was using the G&G mid-cap (79 round) metal magazines and initially there did seem to be a feeding issue that would result in poor firing capability after every magazine change - however this had disappeared after a few hours so I'm putting it down to the gun "bedding in". The adjustable hop was nice and easy to use, I had a small tinker with it for some of the game arenas that I took a 'longer-range' approach to, and it seemed to adjust very nicely using the supplied 0.20g BBs. I found using the stock to it's most-extended-minus-one stop was easiest for me, but then I am a lanky sod with long arms; but the stock was very easy to change on the fly, which I happened to do a few times - compacting it in when going CQB. As I mentioned above, I bought the 'L' variant with the longer barrel. Whilst not a drawback or bad point on my experience, there were a few times where I could have done with a shorter barrel - but these were only in the very CQB elements.
One thing I will say though, I bought the gun based on the very highly-regarded reviews from this site, YouTube and other airsoft communities; especially drawn in by its good (for the price range) internals, robust construction and light weight. Now I won't shy away from the fact that I gave the gun a 'good show' if you will and certainly wasn't afraid to haul it around whilst I was crawling on the ground, sliding into cover, etc. I have now found that the barrel and rail do have a slight wobble to them as if it has come loose somewhere. When I have a bit more spare time, possibly this weekend, I'll strip it down and have a poke about and work out what's come loose. But from a good solid 8 hours of (ab)use, it fared very well, was above my expectations and whilst I do have an itch to replace it, that's in no way influenced by the guns performance but more for my own thirst for something 'new'.
TL

R: a solid gun that provides a really good entry into airsoft without breaking the bank. It has the versatility to hold up against much more expensive hardware, and quite frankly p***es over the cheaper alternatives.