for 35 points extra, i would think GO is worth getting it. SL is only good for CX, no benefit at all to fly at other OW carriers. with GO you get extra luggage & lounge with CX & OW.

Be able to take the person fly with you into lounge is a good thing.

GO will get better treatment than SL and I think it is really the minimum level as a VIP frequent traveller. CX got too many SLs.