Greetings!
In the FWIW category . . .
I have both KWG and WeatherMaster. I did the trial time for both of them and then purchased WM. I liked the view of KWG better, though, so I then picked up KWG (pre 1.3, which they recently released, IIRC).
WM is the better of the two products, imo.
I set up my world in both products and then used them both to generate the weather. After doing a compare, WM won for several reasons.
Both programs do allow a lot of customization. KWG has a XML file that can be modified to create a world's data. WM can be customized through its GUI. However it is done, custom weather can be created, down to the chances of it occurring. Each allows precise control over the weather, at least as far as I understand how the weather happens! KWG does allow game rule effects to be entered and displayed. (For example, KWG comes with d20 rules on how light wind and rain affects skill checks. Again, this is part of an XML file and could be done for any system.) I found WM to have the edge here, mainly because I didn't have to learn or figure out an XML file. While it isn't difficult, WM has help and a complete GUI, including showing the weight of a storm event happening. KWG also "hides" some of the things it can do in the XML file. For example, they don't mention that you can set up the world, including axial tilt and other statistics. I was also not sure if setting that data made a difference in KWG. WM has it all in a better GUI interface, and running the same conditions with different axial tilts does make a difference. I am not saying KWG doesn't do this, I am merely saying it wasn't obvious it does.
Visually, it is very close. At first glance, KWG is very nice for seeing multiple days, perhaps even weeks, at the same time. This allows for a nice comparison. WM only shows weather by day and so the user must switch back and forth between days. <more on that in a minute, though> Both interfaces allow notes to be entered for that day. At this point, though, I am pretty biased for WM, because I have been using it for nearly a year now. KWG is nice but after getting used to WM, I can find what I want when I want it and quickly.
In terms of weather and its events and effects, WM wins hands down. They both give temperatures, wind and weather effects. KWG does give Dark Time, when the moon isn't out as well as the aforementioned rules. WM gives pre-dawn, dawn, dusk information. WM gives visibility information, horizon indicator, wind speeds and temps on an hourly basis, multiple moons (I heard KWG1.3 does this now), special weather events, cloud ceiling and thickness, accumulation and effects by altitude, longitude and lattitude. It sounds like more than you need but it is nicely summarized and easy to find without being too much, imo.
(I had a situation come up in game where a character shape shifted into an eagle and wanted to see what he could see. I had no clue. WM allowed me to enter in the height the character went and the height of any landmarks to see how far he could see! It was so cool, because it told me exactly what I needed for the situation. It could also be used for someone up higher, in mountains for example, looking out across a valley.)
KWG does seem to be currently supported while WM doesn't seem to have done anything in several years. I did get some good reponses from the people who do KWG in terms of tech support. Emails went unanswered to WM. However, in terms of tech support, I needed no help in installing or running either program. I was merely trying to find out if they were planning updates and asked about a few capabilities of the programs. As I said, I got no response from WM but KWG did a good job of getting back to me.
However, the thing that really won me over to WM was the reports. WM reports are hands down so much better than KWG. KWG has weather reports showing storms and daily reports. WM has that and so much more. And I found WM's daily reports to be much better than KWGs, so even where they cross over, I thought WM did a better job. It can output precipitation by month and season. WM allows you to enter your own calendar and print it out, including moons and what phase they are in. WM also prints out sunset/sunrise for a given longitude/latitude for the year. WM allows mutliple output for its reports, including PDF, excel and HTML. All of these are a great help! And I am sure I am not remembering all of them, as this is all off the top of my head.
KWG is not a bad program. It does have some nice features and its (new) price is pretty reasonable. However, WM does most of what KWG does and so much more. The report capability of WM is what won me over in the end because of how powerful and how much I could do with it.
I hope this helps! If you have any questions, let me know!
edg
