Trail shoe recommendation

Do quite a bit of trail running, so might purchase a pair of proper trail shoes - need something that I could wear on both trail and roads (I run on roads to get to and from the trails). I normally wear Brooks GTS Adrenalines (2E) - do I just stick with these?

depending on the severity of the trail, from experience i would say you could just use your road shoes?

....or go for something that's a compromise e.g. Mizuno Wave Harrier/Ascend

Could do. Or could try something like a Newton Terra Momentus or a Saucony Jazz Trail. I used to run in the latter, but found they got a bit sore after 10km or so. Now testing out the former and have been good so far - much lighter shoe, but with a bit less grip as well. Having got lost on my first run in them trying to avoid swimming through a flood (really) and ending up going a lot further than expected, was happy that no problems with them!

Brooks do a trail version of the Adrenaline shoes. I think they're called GSR or something similar. I'm an Adrenaline gal and decided to try their Adrenaline Walker shoes for walking and they're perfect for me. the next time I need trail shoes (I currently have Saucony Peregrine) I'll be going for Brooks trail shoes too!

Big thumbs up for the Mizuno Wave Harrier, I use a pair for mixed trail/road, and find them excellent. 

How much road are you talking about? The harriers are an excellent shoe, especially in the mud and OK for short stretches of Tarmac, but the studded sole will wear quick on long tarmac stretches, and is a bit skittish on wet roads. There are much more road friendly trail shoes than the harrier if this is the majority of the route.

I use Adrenalines on the road and have Wave Ascend's for muddy trails. Never had a problem. The only time they've not had enough grip was on a mossy covered concrete path which I think anything would have struggled with. I've used the Mizuno's on the road as well and they've been ok.

I also just bought my son a pair of Adrenaline GSR (think that's the right combination of random letters), which are the off-road version of the Adrenalines and they look good, but he won't let me get them dirty trying them in the mud.