Some interesting comparisons and expectation here: new product vs used, 16Mp vs 6MP or less... 30% lower price is not "significant"... ;-)
Anyway, my 2 cents... "real" CCDs have 2-5 years then the "hot" cameras will be CMOS.
I've been testing small planetary cameras for double star work for a couple of years. As near as I can tell CMOS hit parity in that application about 2 years ago (QHY5LiiM, Skyris 618m). CMOS is close to or at Parity with the lower end EMCCDs this month (no typo... ASI290m vs several EMCCD cameras with TI sensors). These are small, typically uncooled, high frame rate CMOS cameras...
The biggest change will be in how you use the cameras.
1) With 80% plus QE and < 1e read noise, you don't need 2 hour subs... you are effectively photon
counting... Lot's of shorter subs will also cover the lesser well depth and fewer ADC bits.
2) Binning is always done in Software for CMOS... auxiliary optics, like stronger reducers will be the order of the day
3) CMOS sensors do a self calibration. the new sensors do a pretty good job of it too, so darks and flats are likely to
go away (maybe). You may have to do darks and flats with every image in critical applications since the internal calibration
can't generally be controlled. The single biggest discussion point for us with CMOS, BTW.
4) We don't have CMOS specific software yet, that too is needed. Many CMOS chips have a number of "modes"-- low light,
High conversion, high dynamic range, calibration control... AFAIK, there isn't any software that knows about any of this.
5) New techniques... New tools can almost always do things the old tools can't. Of course they often don't do
some thing the old ones did or do them in a different way. CMOS is a new tool... and it's different.
6) New image processing routines- I haven't looked at the deep sky processing lately, planetary folks are doing a lot of high end math on the images with great effect. We do a lot of Fourier on the doubles (Speckle) and Bi-spectrum/triple correlation is coming on-line. Bi-spectrum should work on deepsky images too.
Bob, as a first camera, I don't see how you can go wrong with either choice. I was looking real hard at the ATIK414ex-m to use both on-Sky and with a spectrometer. I went with the cooled ASI290m because I know it would work for doubles, what I do most. I'll have to learn how to use it for spectroscopy, but that's half the fun. I'm sure it won't be the last camera (CMOS?) I buy, not even part of the discussion.
I just got my CAM84 board going (CCD, ATM forum) and am waiting to hear my Cooled ASI290m has shipped... good time to be doing AP.