Leo,
It is certainly possible that Fritz' other flasks may be of the highest quality, though I have never bought them, as far as I know. If you say that your sanderianum flasks came from him, then they certainly looked great.
Nevertheless...
When I spoke with you about getting kovachii flasks, you told me that the ones you had were still small. That was nearly 4 months before Glen Decker sold me these ones, and he didn't mention anything about them being really small. And the fact stands: I paid $400 per flask for tiny plantlets, and a low count. Personally, I would hope that a grower with integrity would wait until the flasks were ready to release them and charge that much.
If you say that this is not typical of Fritz' work, then I'll take your word for it. This is, however, the only experience I've had with hiim directly, and it doesn't make me want to be charitable in my estimation of his services.
My kovachii are growing well, so I'm a lot less frustrated with the flasks than I was a few months ago.
As Ever,
Matthew Gore