u/aviator1212

Dear all,
I have an Arc Ultra + Sub gen 1 + 2 SURROUND SL.
I thought of upgrading to SUB 4, but I read a thread here in the community it's not worth it.
So now comes the second Q, is it worth upgrading to a pair of Era 300 with current Sub 1 + ARC ultra.
Third Q is Also what will I do with old pair of SL after upgrading to Era 300 ? I had ARC before which I gifted to mom's, now I can't give her the pair of SL unless I get her a Sub, which I have decided against upgrading now.
So dear folks please guide and suggest.
Cheers.