I'm a Dominion n00b, for the most part. I discovered the game just before xmas this past year and immediately bought all of the cards. I discovered Isotropic in January and started playing every night. I was rated ~35 on Iso before it shut down and I switched to Goko.
Despite all the problems with Goko, I've really enjoyed playing against the bots that Goko provides. For someone at my skill level, it's a great way to learn the game at a fast pace. I've played about 500 - 600 games on Goko, almost all against the bots. As a n00b, I found the community on Isotropic to be a bit intimidating-- I played several games where an opponent ended up bitching at me in the chat box because I was taking too long. I eventually stopped playing automatches against strangers because I was encountering a lot of people who were hostile and ridiculously impatient (complaining if a turn takes more than 10s).
Now that I've learned the cards and have a grasp on basic strategy, I'm trying to switch to multiplayer on Goko and am having a very difficult time. The bugs and interface issues are just as bad as everyone says. I get the black screen probably every other day. It randomly moves from browser to browser. Some days Chrome is fine, other days the game will only run in Firefox. Sometimes it will only run on Firefox Nightly. Sometimes it won't start in any of my browsers. I've had many days where the game just randomly dies and times out while I'm playing, which probably sets my rating back. One afternoon a couple of weeks ago I hit reload on probably 40 - 50 hands before I just gave up. I'd finish a game without any issues, then go through a string of 5 - 10 attempts that would hang after a few turns. Fantastic for my win/loss ratio.
Regarding the interface issues, all of the points raised are spot-on. I've spent most of the last decade as a user experience designer (design lead on Gmail for ~3.5 years, among other things), and there are a lot of fairly small changes that could make the experience much, much better. My biggest frustrations have already been mentioned-- I end up discarding things by accident all the time, particularly when playing at "fast" or "very fast," and I can't tell you how many times I've accidentally ended my turn when I meant to play treasures. These are muscle memory mistakes that are the result of poor design. These things often get worse as you spend more time with the product. You get used to clicking in a certain place after playing the game several hundred times, and when an exception occurs, it's very easy to click before you realize that you're not in the state you thought you were. It took me forever to figure out how to find the second page of cards in games that have more than 10. For a while I thought the bots were cheating and were somehow able to buy stuff that wasn't in the supply. These are not issues of paying more attention to the game or learning its quirks-- they are design flaws, pure and simple. One round of usability studies conducted on players of varying skill levels would bring these issues to light, along with a ton of other small things.
There are many other threads on the forum about the other issues-- the joyless adventure mode that requires you to use zaps in order to balance your bad hand against the bot's overly generous hand, the poorly-conceived use of virtual currency, the lack of automatch, the lack of point tracking, etc, etc.
All of those things aside, the thing I find most surprising about Goko is that they are failing pretty miserably when it comes to building a strong community of fans. Yes, I want them to build a solid version of the basic game before they move on to other stuff, but there are so many obvious community features that should have been launched with the game: profile pages, statistics, logging and analysis, spectator mode, friend lists, forums, etc. As someone who is pretty new to the game, I want to connect with other people who are at roughly the same skill level and are interested in learning and exploring the game at the same pace. I want to get better at the game and learn new strategies from more experienced players. It's really hard, if not impossible, to do that on Goko.
I guess the bright spot is that the black screen finally got me to register for this site, which is a real treasure.