So far the MS8609A has been great...no complaints at all...I paid a little over $1400 ...it came with a full Agilent cal (about 10 pages worth of cal data & charts)
I almost considered buying a second one!! I've also had an MS8604A (8.5 GHz unit)for maybe 10 years...still works great & you can often see them now for <$500 (I paid around $1500 10 years ago)..MS8604A noise floor is good, but not as good as some, since it is sold as a "transmitter tester"
MS8609A with:
Opt04 Digital resolution BW (RBW 10Hz)
Opt05 Rubiduim clock (1x10e-10/mo)
Opt08 Pre-Amp (100KHz-3GHz+20 dB, NF=6.5 typ)
Opt31 Low Noise Floor (-112dBm in 7.7-13.2 GHz band)
Opt32 Max Input Range Extension (to +30 dBm, ref:-100 to +40 dBm)
There is a posting here on how to turn on option 02 FFT & the ethernet, if they accidentally get turned off by someone
https://www.eevblog.com/forum/testgear/anritsu-ms860xa-(and-likely-ms268xa)-options/msg2821740/#msg2821740