R&S have a deal on the RTB2004 package at £2900 (3390 Euro)
https://www.batronix.com/shop/oscilloscopes/Rohde-Schwarz-RTB2K-COM4-SP.html
This is fully loaded 4 channel, 300MHz with all options (MSO, Decode, Protocols etc), 4 probes, logic probes etc.
Sounds like a pretty goo deal to me is it worth it?
That is a good deal compared to retail price. That, OTOH, is arbitrarily pumped up by manufacturer, because they are big brand and they think they can.
Look, nobody will take responsibility of choice from you.
RTB2000 is not worse scope than SDS2104X+. Nobody will claim that.
Is it better?
I personally think it is a bit more polished at the time, if nothing else because it is longer on the market. God knows it was buggy mess when it came out. But, despite taking really long, they fixed most of the obvious stuff. Some things are still unsolved, but not obvious stuff.
It is also mixed bag: Decoding is really nice on that scope. But you have only one decode. Wait, that is wrong there are 2.... Yeah, but those 2 are simplex. So you want to decode UART you can decode only 1 uart if you need RX and TX. On SDS2104X+ decoding doesn't look so nice (but does the job neverthless) but it has 2 full duplex decodes. R&S would try to sell you this as "we have 4 decodes". So If you do only simple stuf, and 2 simplex decodes are good enough for you , RTB2000 will do good job. If you need to look at 1 SPI and 1 UART bus at the same line both RX and TX, you cannot do that on RTB2000, but on Siglent it's no problem.
Siglent has arbitrary math, 2ch and math chaining. It can do some stuff RTB2000 math cannot do, but RTB2000 math is already pretty good for average user.
So depending on what are your priorities. When I'm in a situation that I need to decide but cannot make a simple clear choice, i literally open Excel, enumerate on the left points I find important, and in several columns I give grades from 0 to 10 for each options. I sum it up, and then usually becomes obvious. Put all the technical merits inside table, but don't forget other factors if they are important to you.
For instance, for a educational videos maker, availability of ready made edu materials mith matter more than cutting edge performance. Or you have customers that care about if your lab looks either "old school" or "super modern and hip" (apple style)..
Don't forget to give points for price... If in your comparison RTB2000 comes on top, fine, but also make sure that it is as much better for your needs as it is more expensive...
For a small business owner, for instance , it would make more sense to get 2 SDS2104X+ than single RTB2000. Siglent is more than good enough (actually make that way more than good enough) to do the general purpose job, and I could have 2 engineers or technicians working at the same time, instead of waiting their turn.
In the end, it is you who have to make a list of priorities and decide.