steve wrote: very many people are using MX for their production system. It appears to be as reliable as Cumulus 1
The main decision is whether you are happy with the different architecture of MX, and whether you can live without those facilities in Cumulus 1 yet to be added to MX.
That adjusts my understanding, and I am adjusting my plans. In the very short term, I'll keep running the old hardware including the old PC and C1 as my "production" environment, while using the new hardware for further testing, and preparation for cutover.
In the realm of testing, I intend over the next couple of days to do some 24-hour temperature offset comparisons, as a partial exploration of my observation that the console seems to report indoor temperature elevated above what it would otherwise be, not just as a spike when one or another of my abnormal events occurs, but also as a steady-state difference between the case that, for example C1 is running, versus nothing, or MX, or WeatherLink.
I also intend soon to do a trial transfer of the 5-year history on the old PC to new, as to which I believe there is a detailed entry in the FAQ, with test posting using C1 to a temporary trial site.
Following up on your comment here, I intend to explore the trial MX installation I made here by a rather minimalist method, seeking problems or opportunities to fix or pursue before making that my production site. My two main known issues with my trial installation are that I lack the ability to view history data graphically locally (the old Select-a-graph function), and that the trial web site I generated lacked updated graphs (the Trends page). The thread posted by mcrossley may point me a path to a wonderful solution to both problems, but may be beyond my reach. Clearly I need to spend time looking about in the abundant MX postings.