I've thought about starting a thread about MTB tyres before, but never bothered as hardly anyone ever seems to come to this board!
In my experience, cheapo MTB tyres give good p*ncture resistance, but next to no grip. The more expensive tyres give much better grip and sod all p*ncture protection!
I've thrashed various BSOs with cheap tyres through the woods with a p*ncture count not much above zero for years. As soon as I got something half decent with more expensive tyres, I was fixing flats several times a week! Thorns being the main offenders.
The thing is, once you've ridden with tyres that offer good grip, you really don't want to go back to anything else.
I've settled with Nobby Nics as I quite like them and they seem to offer a decent amount of grip. However, they are prone to p*nctures IME so I started using
Panaracer Flataway liners towards the end of last summer. I cannot recommend these highly enough! I've only had one flat since and that was a massive thorn that would have gone through pretty much anything.
I always used to mock people who used tyre liners of any sort (I have no idea why!) but these are excellent. I personnaly don't notice any difference in the feel of the tyre when using them (apart from a slightly different noise on tarmac) so they are a great way of making a nice grippy tyre that is otherwise useless against anything vaguely sharp a really good tyre....