I get all three of the magazines mentioned plus "The Whip" as an ADS member and they all have their virtues. I haven't been overly impressed with Driving Digest and only subscribed this year because they offered a special rate at the National Drive. I'm already rethinking my subscription but the one thing I LOVE about the magazine is the training articles by Andy Marcoux. Those are FABULOUS!! Utterly invaluable and very nearly worth the subscription all by themselves. Otherwise it's mostly ads and one-page antique carriage articles and a bit of recreational driving stuff. It just feels...I don't know, flimsy. All but those one or two great training articles in each issue are usually no more than a page and the overwhelming impression is quarter-page or half-page black and white ads. The current issue is 64 pages.
Carriage Driving World has had some problems with timely delivery but is one of the best magazines out there when it's actually available. Each issue has an excellent training article by Hardy Zantke, an "Ask Muffy" column with Muffy Seaton, coverage of events big and small in glossy full-color detail, and almost always something about the VSE's. Unfortunately since the issue that was due out last October and finally came out this spring I haven't seen another one and there's nothing new on the website either. *sigh* The last issue was 60 pages.
AmeriCan Carriage Driver is a VERY good magazine with more of a recreational driving flavor than Carriage Driving World. Again, lots of VSE coverage and some very useful articles on "How To" in each issue. The latest issue was 46 pages and featured book reviews, harness reviews, places to drive your horse, old driving postcards, a featured equine artist, new products, and articles on various sleigh ralleys and CDE's along with some training articles. It's not as full-color glossy as Carriage Driving World but feels solid and satisfying with plenty of content. Almost everything is informative, not the same ads over and over.
The best magazine, design- and content-wise, is The Whip but you have to be an ADS member to get that one. It's well worth it in my opinion! That's the only membership I have where I feel I actually get my money's worth in return.
Leia