Yes, I am familiar with his work, and have been using his ideas for almost exactly a year. I have to admit that I tweaked them somewhat to produce a slightly faster system with more trades. I have made about 15-20% on that part of my portfolio over the year. I am looking forward to seeing how the method will fare over this downturn. Currently I am long UUP, TLT, IYR and I am short MOO, DBA, USO, SGG. Some of these are probably a bit redundant.
Faber states somewhere on his site that about half the trades are winners and that the average winner is much larger than the average loser. This has been exactly my experience. I have made about 20-25 trades, and three, all of which I held for a long time, were big winners. About half my trades are losers; I rarely lose more than 4%. There is a fair bit of whipsawing; I bounce in and out of things frequently until I catch a wave. One time I made 6-7% on FXY and ended up giving it all up. So this is like all trend following systems in that you need to be able to endure some rock and roll. In addition, signals tend to come in groups. I can sit around doing nothing for weeks and then get five or six signals at the same time.
I have backtested this with my own adjustments on several vehicles and it is my impression that commodity etfs will trend better than stock etfs. I do not think this works very well with broad based stock indices (with the notable exception of emerging markets). Stocks are too volatile relative to their price changes and I think you would get whipsawed too much. As for bonds, I think they trend well also. Some have certainly had a great run this past year, but I did not trade any of those, since I got to the party too late.
Let me know if you have any other questions or want to hear about my tweaks.