@Dave Atom:
I wouldn't say that the DS1054Z is a bad scope. It just has its flaws that are expected from a company that had to cut corners on everything to get the price down to have even the slightest chance of getting into the market.
So far I haven't run into any serious issues with my scope and really like the 24MegPoint memory, which seems to be one of the things the Rigols really shine at: Every Rigol-Scope comes with tons of memory compared to other brands - even Tektronix and Keysight don't offer that amount of memory in their devices.
What I absolutely don't like is the fact that the Firmware behaves inconsistently. Sometimes I get immediate responses when turning the offset-knob, at other times (same settings btw.) the scope seems to be bogged down by some random stuff and it takes a while for the changes to appear on screen. Also the FFT, as seen in a video by Dave, is horrible.
But it bugs me that I have a potentially horrible looking ADC-Clock in my scope, as well as what appear to be Schroedingers LDO (It could be oscillating, or not... I have to look at it to know)^^
So my Advice: If you can live with the quirks of the Rigols, get one. If not, get an equally expensive Tektronix TDS-Scope on ebay and a healthy supply of electrolytic capacitors
Btw. I suspect Siglent, Owon and the other chinese brands to have similar problems. Can somebody check their devices?^^
Has anyone checked the DSA815 for any problems similar to the Rigol-Scopes?