New shoes. Trail or regular?

My trusty Nike Triax GTXs are approaching retirement, & it seems they are not very easy to replace.  My outside running is mostly on footpaths & bridlepaths - gravelly & sandy as well as muddy from time to time, but I'm a bit of a fair weather runner so I tend not to run outside when the mud is knee deep!

I'm training for a trail half marathon so if I'm going to change shoe I probably should do it soon-ish.  But is it worth going for trail shoes, or should I just stick to ordinary Triax's?  I'm used to Nike shoes & find them comfortable so don['t want to switch brands, but can see it might be time to switch shoe type.  One of my running buddies reckons the hassle of keeping mud etc out of the treads make trail shoes more trouble than they're worth, citing the need to stop to clear several pounds of gunk off the soles halfway through a run. 

I've also read that trail shoes tend to have less cushioning because they're designed for use on softer surfaces.  I get shin splints, so cushioning is quite important to me. 

What are forumites experiences?