This has a lot of good things going for it.
The silicone coating is thick, resilient, and releases the hamburger patty (intact) with little effort. This is such a good idea that I'll very likely never buy another press that doesn't have a silicone lining. Those of you who have tried other presses, particularly the metal ones, and had the patty stick and fall apart after the press is opened probably know what I mean.
The ram allows very firm pressure for a tight, round patty.
The size is really good for a quarter-pound burger. I tried third-pound burgers with mine, but I think a larger diameter would be better for those as they came out thicker than I wanted them. It would be nice if they offered this in two sizes, with a larger diameter for heavier burgers. That way the heavier burgers could be made bigger (in diameter), without getting thicker.
The thumb print seems like a gimmick, but does work, particularly when using meat that has a lower fat percentage. I've found that the higher fat meats, like the traditional 80% meat/20% fat chuck, still tends to end up more like a meatball than the lower fat alternatives like 93%/7%, especially when using more meat. This is because the higher fat content meat shrinks more, and a small diameter with a thick middle will turn out looking more like a ball than a burger.
The little silicone cap, which comes off for cleaning, is nearly impossible for me to get back on. The tolerances are so close that it sometimes takes me longer to get that thing back on than to make the burgers themselves. Perhaps individual units vary a bit, but the one I have needs either a little larger cap, or a little narrower post. I tried drilling a small hole in the post in case air pressure was the problem, but it didn't help. Eventually I'll probably try sanding the post to reduce the tight fit, but I haven't done that yet.
I make the burgers by purchasing 2-3 pounds of 93%/7% ground chuck that is very cold (but not frozen). I use a digital kitchen scale to measure out four ounce balls of meat. I put them in the press one at a time, flatten them with my hand, then press down on the ram with all my weight. This makes crisp, round burgers that won't fall apart later when cooked. The soft silicone lining means you can rap it against a cutting board and it will pop out in one piece. (Hint: if yours is leaking around the edges, try using colder meat. Warmer meat is more likely to flow around the gaps and also to stick.)
As I make each patty, I put it on a foil lined baking sheet, thumb print side up. When I've finished all the patties, I put a sheet of wax paper over them and put them in the freezer for a few hours until they are hard. Then, I take them out, put them in foodsaver bags (ziplocks will work too), separating them with squares of wax paper cut from the sheet that was over them while they froze. Then the bags go into the freezer, and I can pull one or more patties out whenever I want to cook them.
To cook them, I put them on a hot, preheated cast iron grill pan, or outside on the grill, thumbprint up. After around 4-5 minutes (time will vary depending on the temperature of the pan or grill), juices will appear on the top. That means that the burger is now thawed all the way through, because as long as ice remains in the center, the top will stay cold and juice-free. At this point I usually carefully lift and turn the burger about a quarter turn and leave it for another minute for nice looking grill marks. Then, I flip it and leave it for about the same amount of time (including the quarter turn). I use an instant-read thermometer to check the center for doneness, around 160 degrees for well done. If it is close to 160, you can go ahead and take it off as the internal temp will rise around five more degrees after you take it off the grill. Just don't cut it for a few minutes or the juices will all run out due to the heat.
I put the buns on the grill for a short time to toast them on the side that faces the burger. It makes the bun stand up to the burger and condiments better, and lends a nice warm fresh taste to the whole thing. I also use field greens instead of standard lettuce for a more upscale taste and look, but other lettuces, like romaine, also work well.
Overall, I've found this to be a very cost-effective way to make my own, lower-fat burgers for much less money than buying the premade frozen versions.
Recommended, with a few reservations. It isn't perfect, but this is probably the best press currently on the market.
Sean P. Logue, 2008