I have an MK-III with both wireless receivers. I like it, but am having issues with it.
I know the temp is off and the rain gauge is not working either. There is a second data logger that I am using, but cant remember what it is. Serial port. Transfers info every few seconds instead of 15.
With that said-I am looking at getting a Davis as a replacement. My wife is getting a grant for something at work, and is donating it to my science department.
If you do go with a different MK-III, we can work out a deal on the loggers, but it would not be until at least April. if not, Davis is always a solid choice.