RE: Eclipse 7 Spectra channel selection
The frequency is set by a couple of small switches that require you to remove the Spectra from the transmitter so no, you can't have it stored in memory and automatically changed when you select another model setting.
However, I don't find this to be too much of a hassle since I tend to have all my models on the same frequency (can't fly more than one at a time :-) and have a few spare receiver crystals just in case I do have to switch channels.
I've only had to change frequency once, since here in NZ we have 27Mhz, 36Mhz, 40Mhz and 72Mhz so frequency clashes aren't all that common -- especially at a field like mine where there are normally only a handful of fliers on a weekend.