I feel that answer is a bit misleading. Aren't the keywords "high speed" here? You can find all kinds of instruments in professional telescopes, including some based on relatively exotic designs (we aren't getting Aladdin III In:Sb sensors in our cameras any time soon, I think). CMOS based architectures are of course widely used in fields where high speed is possible or desirable (photometry of occultations for example, solar observation etc...). But CCD still reigns in imaging applications. I was so surprised by the above statement that I double checked what current major observatories use as imagers
ESO Paranal - http://www.eso.org/sci/facilities/paranal/instruments/index.html - have a look at the detailed description of the instruments, too many to list here
Gran Telescopio Canarias - http://www.gtc.iac.es/en/pages/instrumentation/osiris.php#Detector
Subaru - http://www.naoj.org/Observing/Instruments/SCam/
If the purpose is going deep and long exposures, everyone seems to still be using CCDs
Not that I disagree with the increased usefulness of CMOS based sensors in many fields in general - but do you have examples of CMOS sensors used for image acquisition in fairly long exposures?
What I said was "CMOS...is now beginning to
displace CCDs in research instrumentation". Not "CMOS has
displaced". The instruments you linked to are all relatively old; some were completed in the 1990s, the rest commenced development before the recent surge in CMOS performance. They generate science, not income, so they won't be replaced unless absolutely necessary. It's going to take time.
Also, there's a certain amount of inertia imposed by the different readout electronics involved with CMOS. Observatories like to standardize on and re-use existing CCD controller systems as far as possible, for multiple instruments or when upgrading a sensor in an instrument (google ULTRADAS and SDSU-II for example). Switching to CMOS will require a new system, more development time, new documentation, new training, and above all more funding, which is really hard to get.
Another reason is that we still await large
low-noise CMOS sensors (the same reason why there are still no CMOS MF digital backs). Large research telescopes have giant focal planes to populate with mosaics of imaging sensors, so the availability of large CCDs keeps them at the forefront.
You are right insofar as CMOS usage in research at present is mainly in the high-speed or timeseries niche. Any scenario where you have to take many frames, is where their low readout noise per frame makes the most difference. Their other great advantage, low dark noise, is a bit moot in research where liquid nitrogen cryostats are normally used to take CCD dark current down to an acceptably low level. But modest (peltier based) cooling on CMOS is around the same level (google CentralDS for example), and I can imagine that moving away from the hassle and expense of cryogenics (not just in plant and materials, but also because technicians must be employed to refill dewars 2 or 3 times in every 24 hours period - the sensor must never be allowed to warm up) will be very attractive to observatories.
You ask if I "have examples of CMOS sensors used for image acquisition in fairly long exposures"? I presume you mean discounting amateur astro-imagers, who use both off-the-shelf and modified CMOS DSLRs for exposures running to hours net? Well in research there are areas like wide-field auroral monitoring which use similar setups.