I haven't tried their Balti paste, but their Kashmiri masala is one of my staples. It is easy to overdo it, if you use too much, but used in moderation it can add a definite je ne sais quoi to a curry.
I bought Patak's Balti paste in order to try a recipe which seemed to show promise, but it was rubbish - not from this site, incidentally.
I will, however, give the Kashmiri masala (I assume it is a paste) a try, seeing as you recommend it.