I have over 30 vac pots in my collection, from New Hario Nouveau models (my favourites) right back to vintage 1930s style Coffee Robots from Farberware and a late 1930s Silex Junior 3 cupper model. I‘ve used just about all of them and I base my review of the Yama on these experiences.
The Yama 5 cup model with the flat base that www.baratza.com sells is about middle of the road as far as vac pots go. Nothing exceptional, but neither is it a bad vac pot. One of the biggest pluses for it is the price. At around $40 or so, you get a nice sized vac pot with a cloth filter set and a few extras in the box.
The next plus is the cloth filter. Out of all filtering devices for vac pots, I believe the cloth filter / ceramic combo is the best. The Yama uses a metal filter, which is a slight step down, but not a big deal. You get nice clean, full bodied coffee that still contains many of the coffee oils that paper holds back, and you don‘t get the chunky coffee that glass rods and all metal filters deliver.
Using the Yama is pretty simple. It has a flat bottom, sight lines for 3 and 5 cups, and comes with a metal wire trivet for electric stovetop use. Put it on the stove at around 7 or so to let the water heat up. As soon as you see wisps of vapour come out of the bottom pot, then attach the top (with filter and ground coffee in place. As the trip north commences, then stir a bit as it continues to rise. As soon as the kick up has completed, turn your heat source down to 3 or so, just enough to keep the water up north, and wait for about 70 seconds. Remove from heat, and watch the kickdown. Remove the top, and wallah, vac pot coffee.
One more positive before I get into the negatives - the all glass construction is great, and the rubber gasket for the syphon is good quality.
A few negatives - biggest peeve is that there is too much water left in the bottom... the syphon should be a millimetre or two longer. Use a bit more coffee than normal (ie, 1.25 tablespoons per "cup" instead of 1 tbsp). The other peeve is that the pour spout is poorly engineered - it spurts coffee if you try to pour too fast. It doesn‘t take a rocket scientist to design a good quality pour spout, Yama.
Other than that, there‘s not much to complain about regarding this vacpot. It‘s a good starter set, and if you‘re in the market for one, consider it.