1054Z is also faster and has more memory, but I am worried about the software bugs with 1054Z.
The DS1054Z had many bugs. Rigol fixed many (most?) of them, which is why it's beneficial to buy something that has been on the market for a couple of years or more. We may find new bugs, but meanwhile we make use of the tool and it works for us.
If this scope will do what you need and is in your budget, worry less and make more stuff. If you have a higher budget, you might consider a higher-end scope if that will help you worry less.
Thank you very much. So am not gonna make a mistake buying a 1054Z instead of 1052E ?
My budget is max 500$, so high end devices are for now out of question.
You won't be making a mistake with the 1054Z. If it comes from current inventory, it will have the latest firmware 00.04.04.SP1. To the best of my knowledge, all bugs have been eliminated EXCEPT for a spelling error "Pluses" where it should be "Pulses". I can live with it...
I would suggest you read this thread only as far back as Nov 2016. That was when the lastest firmware was released. Issues with firmware older than that seem to have been fixed. Who really cares about issues at the margins way back when the scope was first introduced? They have been fixed.
There are alternatives, of course. The thing is, they cost a lot more money.
As boring as it seems, do try to read the User Manual. These is a lot of capability in the scope that you just won't find unless you read about it first. It has a lot more capability than just displaying wiggly lines.
In fact, you can download and read the manual while you wait for your scope to arrive. At least skim over it and see what it can do. You can get down to button-pushing when the scope arrives.