Thoughts and Observations
Over the last several years I have had the pleasure of working with about twelve of Protostack's AVR Development boards. In fact, the first custom AVR project I ever built was developed on a Protostack board. The company pays close attention to the quality and features it builds into each board, and actually takes into consideration every piece of user feedback it gets from its customers. Daniel Garcia, the company's founder, designs these boards himself, and makes revisions to them often. This leads to a better product and not something that is stuck with antiquated features or lack of newly discovered features.
I absolutely love the large prototyping area you get with each of Protostack's Development kits, and this is why I choose them for all of my prototyping projects that require an AVR. The fact that the boards are easily stackable with the other prototyping boards he sells makes this a complete ecosystem that any AVR developer should consider using. One of the biggest selling points for me is that all of the holes in the PCB are through-hole plated. This makes for a more solid solder joint, and helps with preventing pad lifting on solder joints that may have been heated a little too much. Additionally, the boards pads have all been coated with solder at the factory, and this makes soldering without extra flux a breeze.
Unlike many of the build-it-yourself development boards on the market, the boards from Protostack feature a bright red solder mask with a very easy to read white silk screen. This makes identifying ports, components, and rails much easier than a PCB of lesser quality. That brings up another point that I would like to make, the FR4 PCB material used in the creation of Protostack's PCBs is very well constructed, and features a nice heavy solder pour on both the top and bottom layers. This aids in both a better quality signal, as well as excellent thermal dissipation from components that may be heat sensitive.