why do you give the option of 100MHz, 150, and 200? why not just 200? why should any one want to be at 100/150 when they can have 200Mhz??
I think that some day it is good to open new thread where handle things what are related to analog channel quality and frequency response together with true A/D conversion samplerate.
I think this is important to look these things without connection to one scope manufacturer/model.
These things are fundamentals for understanding digital oscilloscopes and also for avoid some possible "hidden" effects to measuring accuracy and for avoid some problems.
It is not so that as wide analog channel as can made is better - specially if talk about realtime measurements as FFT or single shot or other measurements where we use realtime sampling and not repetitive sampling (Rigol named id "egual time...")
There are some good readings for this:
http://cp.literature.agilent.com/litweb/pdf/5989-5732EN.pdfhttp://cp.literature.agilent.com/litweb/pdf/5989-5733EN.pdfhttp://cp.literature.agilent.com/litweb/pdf/5989-3020EN.pdfhttp://www.emcsociety.org/Presentations/IEEE%20Seminar%20Scopes%20and%20Radar.pdfAs long as do not rise (by mod) samplerate there is growing problem with aliasing if make analog channel more wide.
But also this problen must not overlook. Only need undertand that oscilloscope is always some kind of compromise. Good there, error there. What you see is sum of errors summed to original signal under test.
With digital camera you can easy see if picture is good enough for tell what is real what you take picture.
Scope situation is different... only "window" to signal is your scope display... but, sometimes it is wrong. How to avoid this... design scope so that all fundamentals are ok.
Example if you look FFT and signal under test include components what freq go over Nyquist.. what you see.. you see totally lies about signal under test. You can see signal (example just wrong frequency high spike... but real signal do not have it at all. Why... you read papers then you know.
It is like bad radio where you listen signals totally in wrong frequency only becouse front end and mixer etc is toy.
I hope some with good english and more time open new thread for handle these fundamentals...
You do not buy best camera by looking only more pixels... you do not get more good oscilloscope if you look only samplerate and MHz number.