Yeast Washing: Practical limits?

So, I've read through a bunch of the yeast washing thread, but there's an awful lot of info there, much of it conflicting...

Anyway, is there any real practical limitation to what yeast cakes can and cannot be washed successfully? Upper OG limits, too highly hopped a beer, certain grainbill charachteristics to watch out for, etc?

Not long ago, I washed yeast for the first time from an IPA I brewed, and I pitched one of the jars of yeast (with appropriate starter) to an American stout, right around 1.056 OG. That stout should be ready to keg in the next week or two. I could swear that I've read somewhere that yeast cakes from stouts shouldn't be reclaimed for some reason, but it seems to me that yeast is yeast and, if properly washed, should be just fine... Am I oversimplifying, or are there things I need to be aware of when deciding whether to wash or not?

I reuse yeast and, with the exception of sanitation, I largely disregard popular wisdom. I collect any used yeast into a sanitized jar and store in the fridge. Labeled of course and wirh a date. When the time comes I decant and throw into an appropriate starter, chill, decant, pitch. If it is a particularly old batch of yeast I will step up the starter very slowly with scrapings from the top of the cake. May be 3 times beforeI do a full sized starter.