Purchacs advice

[GrahamJ]

I currently have. A Tal 4.5" reflector, had for ages little used. In December I bought a Tal 100rs my interest being rekindled.I also have a pair of very good 8x56 binos.my dillema is that I am thinking of buying a pair of 20x90 binos, I am assuming they will be good for dso.If someone with more experience could advise if this would be a usefull purchase, or if I would just be duplicating the potential I already have I would be most gratefull.