Recipe Adjustment Question

I've read in a couple of places that when your modifying a recipe to accommodate your equipment and efficiency, the only thing you should be modifying is the base grain.  I've read that the specialty grains should stay the same.  How do others feel about this?  I've always tried to keep the grains in the same % as the recipe given. 

Also, if I'm adapting, say a recipe that's for a 10 gallon batch to 5 gallons, my first inclination is to simply cut the recipe in half and then go from there.  How should I be making these adjustments? 

With small adjustments I only change the base grains.  When scaling larger, I work on percentages then personal preference.  If I think there is too much black patent for my taste, I'll change it regardless of percentages.

Wildrover,

For what it worth, when I'm scaling down, example 10 gallon to 5 gallon, I use percentages which is the way I believe BeerSmith scales. However, when scaling up, I'm like jomebrew, I get nervous with the dark grains. So I usually put a cap on them based on our particular tastes and make up the gravity difference with base malts.

Preston