So we got to test drive the Portofino yesterday and it's definitely a step up from the Cali T and it's a little larger in the cockpit. We tested it on a lot of twistys that I frequently drive so I can make a direct comparison. The steering wheel is smaller and I don't like that but the car sounds great. It is a throatier sound than the Cali T HS but it has the same shift speed and it barks on upshifts and blips on downshifts. Doesn't sound as good as the 488 at speed but it's not supposed to. I think it certainly sounds better than the regular Cali T and maybe only 5% better than the T HS. The lower rpms are throatier for the Portofino.
I pushed it in a couple of turns and the back end slipped out quicker than I would have expected. I checked the tires on the car when we got back and they had decent tread but I am fairly sure that the wear affected the grip in the corner. The acceleration is noticeably quicker than the Cali T HS but not nearly what the 488 has. This isn't comparable to the 488 but it's certainly better than the Cali T. The seats are comfy and there is more room in the cockpit than the Cali T and of course than the 488. I am not a real fan of the on-screen seat adjustments but it does have an extra feature on the seat adjustment that will extend the front edge for more knee support on longer drives. My M5 had that and it was a nice feature.
My wife loved driving it and she liked the car a lot. She wouldn't say no to having one. Note the grin.