First, to clarify, IPVM has mostly avoided PSIM because (1) general low member interest and (2) lots of bullshit claims by the PSIM providers.
That we have not covered Advancis Winguard should be seen as a negative. Their name comes up infrequently but I do not take that as a sign of their quality (or not). The bigger issue for IPVM coverage is that the company is European and evidently mostly European focused, which means we (and a lot of our members) are less likely to run into them. They also, unlike their shady marketing competitors, seem to avoid making ridiculous claims.
In the past year, one member did recommend them here. While I did look at their website (including their product overview brochure) and it did not raise any red flags, I do not know enough to make a recommendation on them.