You overdriving the input stage, on some DSOs this might looks better, on others worse, but overdrive is an overdrive and when you overdrive the measured result might be everything but ok.
Attached results of similar setup on my Tekway, made with 3 probes :
- original Hantek PP150 probe
- Testec HF512 (passive 500MHz) probe
- Texas 250/II (passive 250MHz) probe
Note, the shape of the overdrive depends as well on the probe BW and the probe itself. With proper HF probes (the ones having compensation for LF and HF, like the Texas and Testec) the shape looks better - but of course it still overdrives. It depends as well on the DSO BW, so when you do such measurments don't enable any BW filters.
As you can see Hantek probe is not good enough to handle fast edges, not only due missing HF compensation (only LF) but as well due the probe BW. The Texas probe looks on 500mV/DIV and the 2.5x overdrive good, but with 5x overdrive it does overshoot too much (it can not be compensated out, so it is like it is). The best seems to be the Testec probe, it does have some ringing but the signal shape is constant (of course more overdrive = more ringing)
It is hard to say if the signal shape on your Rigol looks like it looks due wrong probes, wrong probe compensation, not matching probes, broken DSO or the design itself - or combination of one or more. Maybe someone else (but please, not a Rigol fanboy) could try similar setup and report the results. For me especially the 200mV/DIV looks too bad to be pure overdrive.
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Rigol probably even know that there is an bit more overdrive than expected, but maybe decided to not do anything about. Or they expected to get more, but then recognized that it is within their expectation. Or maybe they simply copied part of DS1000CA series schematics and even routed the one diode but then recognized that "this is not necessary" - choose one or more
Seriously, hard to say what idea was behind, but when you look exactly there is not populated sot23 between the two opamps in input stage - the diode used here (on Rigol CA) does have T2H marking (actually T2 is marking, H is date code) which is HSMS-286C (Microwave detector diode). So when you really whish to "play" with overdrive, the best place is between the two opamps, i would not touch the first part of the input stage, there is nothing wrong (as it is exact the same on my Tekway and the shape looks better even with the crap Hantek probe). But still, wait first until someone else confirm the signal shape during overdrive. These diodes are not really expensive, but who knows if the firmware has been made to work with them together.