Well, I went a head and ordered the Rothco. It came in late January, but I didn't get a chance to test it till last weekend. The version they sent me looks dramatically different from the company's stock photo, almost like its trying to mimic a "premium" pad. Its about a 1/4" too tall, leaving an overhang under the stock that I had to shim (used making tape and thin cardboard to fix). To get it to feel good on the shoulder I had to remove the stock hard rubber trim (can't really call it a pad) on the butt. The soft rubber on the Rothco could be a bit less tacky in feel, but it does do a good job keeping the butt from slipping once shouldered.
Now for the important part, it helps. The length of pull on the stock fits me much better now, but bear in mind I am 6'2". I shot 7 slugs consecutively with it, and it really takes the hurt out. The slugs still push me around, but they no longer bite. After that I ran 60 shells of shot out the gun going after clays. At the risk of sounding like a pansy, I have to say, it really make shooting clays alot more enjoyable.
Here are some pics of it:
and
Its 5"1/4" tall by 1"3/4" wide at the butt end, and 4"1/2" by 1"1/2" at the open, end relaxed. Overall length is 4".
I ended up paying about $10, after shipping cost, for it. Its not pretty, and needed some tinkering, but it works.