I used it in a brew recipe from Randy Mosher's book,"Radical Brewing" for a Scottish Sparkling Ale, a heritage style. The beer is still in secondary fermentation, and he recommends ageing it for three months before drinking, so it's too soon to say how it will come out. And even then, it will be unclear how much of its appeal is due to the acid malt which is only about 10 or 15 percent of the grist bill. If it turns out well, I look forward to trying it in some other recipes.
On the other hand, it looked and smelled good, and tasted about as I'd expect when I chewed up few grains. I think Weyermann generally makes a good quality product.
This goes in all my light colored brews. I use spring water (may as well be RO or distilled - it has almost nothing in it). In those conditions 2% of this malt has hit my mash pH range every time for IPAs and blondes. I have lactic and phosphoric acid on hand for emergencies, but have never needed to adjust the mash pH with those. TIP 1: Buy a few pounds and reseal with a vacuum resealer (you only need 3-5oz per 5gal batch typ). TIP 2: crack the grains or don't crack the grains - it doesn't matter. Just get 'em in the mash tun. The lactic acid is on the outside.