One thing to remember is that bad news travels 10x faster than good news, some individuals believe that their credibility is boosted by saying that 'this product is rubbish' etc. Some will happily post messages on forums to that effect but not provide a shred of evidence to back it up.
The other thing to remember is that the higher the sales volume of any product, the higher the % chance of a product being faulty. I doubt if there is a product, tank related or not, that is 100% reliable forever, and as far as anything electronic goes...

My washing machine almost caught fire a couple of weeks ago, kitchen was full of black smoke.
I could give an example that taught me a lesson years ago. When the UK utility companies were being privatised. We used to work on a 2% error rate. That may sound great, 98% of applications would go through without any problems, just 2% to sort out problems with? The snag was that we were dealing with 10 million applications, so that was 200,000 errors, and they all had to be sorted out, and fast. People tend to get very irate when their life savings are involved.
With aftermarket tank builds being what they are, and DIY skills being a variable, there is always a higher % chance that a board may be accused of being rubbish, when they are not.
What is important is dealer back up, when something goes wrong, how will it get repaired?
The two aftermarket systems with the best back up are IBU and Elmod. IBU is Tankbears domain, he is UK based, and very helpful. Elmod are in Germany, but they are lightning fast with email replies, will answer the dumbest of questions, and even have a sense of humour.
Clark boards are cheap, I have had two, and they were flawless. Easy to install with only a minimum of soldering. The trade off being that what made them cheap was the DIY part. The downside is that when we could buy them directly from Clark we could talk to Clark, and get advice and repairs. They were also cheaper. He gave sole UK distribution to Tankzone, who may not be willing to provide the same level of customer care. It's an excellent example of the difference between a product and a seller. Tankbear sells IBU's and provides customer service, Tankzone sells Clark boards but...
There is another source for some of the Clark boards, not all, but I am not going to reveal it here, or via PM, its down to the seller to market his services, nice chap though he is

. It's not me I hasten to add.
The Tamiya DMD system is a basic, barn door, electronics system. It is also expensive and does way less than the alternative systems that now exist at a lot less cost. Sure you can drive a Tamiya like a stolen car, but it will never simulate a real tank, and there is no way that you can make it do so.
My advice to anyone wondering what to install is to spend some time on You Tube, there are hundreds of videos on there from hobbyists all over the world who have installed all of these systems, and they are a great way to see what a tank looks and sounds like when running them.
Cheers
RobG