Maybe I have read wrong but for me it sounds as some of you writes:
Buy high bandwidth, you will rarely use 4 channels
and other says
Buy 4 channels, you will properly not use high bandwidth anyway?
It goes either way!
Using 4 channels may never happen for some users or it may happen all the time. It was my most important purchase criteria. I already had 2 channels (analog scope). Since I had never used a DSO, I had no idea how important Single Shot would be. It solves so many problems.
In the old days of the analog scope, I would have to butch up my logic or code in order to have a pulse train repeat often enough to stay on the screen. With single shot I don't need to modify anything. I just select single shot and one pass is all it takes. This is a HUGE deal and one of the great benefits of the DSO.
High bandwidth will never be an issue for those interested in audio. My interests are up to around 50 MHz on uC pins and usually not that high. Maybe something in the 2-5 MHz range.
You never said exactly what you want to do with a scope and that's good because you aren't locking yourself into one mindset and overlooking others. Sure, in a perfect world, you would have both channels and bandwidth. Few of us live in that world!
As also mentioned above, this is just a scope. Better than some, not as good as others. When you need something better, you will sell this scope for nearly as much as you paid for it and use the money toward something better. Or you will just consider it a sunk cost and keep it.
I have mentioned that I want the Siglent SDS1204X-E. What to do with my DS1054Z? Well, it sits on top of one of my Comdyna analog computers, it works perfect in that application, maybe I'll just leave it there and fill the hole on my bench with the Siglent. See? It all works out!