The Bell and MacInness books are slightly different territory.
The MacInness book is a very out of date book, many of the turbos mentioned in it are no longer in production, but it has very solid math and a very interesting look into old school turbo tricks for someone who wants to set up a turbo without electronics. It's about the only printed guide that really covers carbs and mechanical advance mechanisms when dealing with turbos, and it has a treasure trove of really interesting old school turbo race engines. In some ways, it's gloriously outdated, like a set of old Hot Rod magazines would be to somebody building a period correct roadster.
Corky really knows his turbos and has built some very impressive turbo cars (disclaimer: The company I work for has ties to his Bell Experimental Group company and runs one of his kits on one of our demonstration cars. We've been very impressed with their kit; it resulted in a Miata that put more power to the ground than several of our V8 project cars have.). His book is opinionated but fun to read and has a lot of very useful formulas, illustrations, and practical tips. It's got a lot of theory but in some ways has a bit more of a practical bent. It's also a bit more aimed at modern cars, though it has some interesting vintage engines as well. There's a lot more about EFI in it, which is really absent from the other book.