One of my "interests"....has, for years, been collecting waterproof gear. Not cheap...especially if you want to achieve any sort of effectiveness. And it could make you wonder why you bother much of the time. Goretex...a topic which would occupy a fairly thick (and rather boring) book is the one everyone has heard of...but it's by no means the Holy Grail. If I had a pound for every time I've got wet wearing Goretex I'd be a fair few quid better off. Then there's eVent' material...as found in a lot of
Rabgear.
http://www.eventfabrics.com/ To be honest I've tried loads of them. £100 is at the cheap end of the market for a half decent "waterproof" top. And don't be fooled by the term "waterproof". A dustbin liner is 100% waterproof...but it makes you sweat rather a lot. The Berghaus Cornice is indeed one of the standards that go back years. It feels like I've always had one...but for some reason have had to buy bigger ones as time passed - can't imagine why
...and they're OK...the present one was around £100 but you need to search to get one for that money at the moment.
I reckon one of the best for keeping the weather out is Paramo. The Cascada is an all time standard...like the Cornice...but IMHO is better and more effective. But a tad heavier. Best place to get Paramo is on Paramo's Ebay "Seconds" shop. See here -
http://stores.ebay.co.uk/ParamoSeconds. A lot of Mountain Rescue people use Paramo.
I used Buffalo gear for years...one of their tops got me the length of the Pennine Way...
http://www.cotswoldoutdoor.com/buffalo. The Mountain Shirt is a bit of an icon. Have had several of them. A totally different principle of keeping you dry and warm though. Rather like Paramo is a very different principle compared to Goretex.
Ever since the pair of us got soaked through by rain coming at us horizontally on Seaton beach I have striven to stay dry. And would probably say the failures outweigh the successes by a considerable measure. And have spent a small fortune along the way...... Ex Army gear, Goretex, eVent, Paramo, Buffalo and all sorts of coatings and treatments...but there's no one perfect answer.
A huge topic that would take hours and hours to research on the net...everyone has their own view and I think the expression YMMV is appropriate.