There was a thread somewhere about the two being compared.
I may be alone in this but I’m resigned to the idea that literally every one of us tastes and interprets flavour nuances differently so what one person thinks or what the gospel says, or what James Hoffman says isn’t automatically true.
The common opinion suggests you get more clarity from a flat (suited to lighter roasts) and more body, richness from a conical (suited to medium) and my experience has always been entirely the opposite. Same coffee back to back on my C40 vs SJ and medium roasts taste unquestionably richer and thicker on the flat, thinner and brighter on the conical. Was the same on my x54 vs a Vario. Admittedly I’ve not tried a ‘higher end’ conical.
There’s too many variables really to accurately answer - coffee, roast type, burr shape and size, and as above, individual taste.