I've subscribed for a year, and i do think it is worth the $25. Compared to something like the Vanguard Fund Family Letter it is not quite so slick, but the level of discussion is arguably higher. It is written by academics (I am pretty sure) and makes a nice adjunct to investors seeking to implement the Bernstein books in their portfolios.
March's topics included: Deep analysis of impact on your returns of the high fees in commodities funds, More on Retail Hedge Fund index products with explanation of high correlation between Long-Short hedge funds/indexes and the regular stock market making them less attractive for us, and their preference for market neutral or macro strategy fund/indexes for the real diversification they could give us, but that unfortunately there are still few vehicles open to the retail investor. Finally the last main article was about a new China ETF soon available in the US.
Every month they go through a lot of market stats on asset allocation market performance, and uniquely give all htis info in several major currencies .
There is also a huge economic forecast/update and predictions on returns from asset classes, and implied equity premiums in various markets.
There is also a good letter to the editor from an investor looking to buy timber lands for diversification, and they explain the pros and cons of the small number of vehicles for doing this.
It has gotten a lot better during the past year. SUbscribers can have access to all the old issues, too.
I'd say I got my 25 bucks worth this year and would renew.
ER for 10 years; living off 4.3% of savings (and a few book royalties ;-)