exterior painting

i have had a search on here for info on external masonry paints to tidy up the front of a house.
the existing is mock tudr/georgian timber panels with textured paint in between.this is on a plywood background, typical 80/90s house build,
the existing paint is in reasonable condition, with a little bit of tiny crazed cracks, oddly on a north facing direction.
narrowed it down to either sandtex or leyland trugard which oddly enough screwfix are selling at £16 for 5lts, trugard smooth masonry paint.this is nearly half the price of the sandtex. too good to be true? or is the sandtex a better quality product and worth the extra at £26/30 a tub
any advice please

TIP: I used to work for a major builders merchants, and have worked for several paint companies.

Go to a proper trade paint supplier or builders merchants and buy TRADE paint as, with most of the brands, it is better quality than the same brand sold in the DIY shops.

....but i never told you that.