Like you, I’m a long term Alfa 4C owner (8 years) and interested in replacing it with something appropriate. My shortlist includes Porsche GT4 and 911T, Emira V6 and AMG, MG Cyberster (an EV), as well as classic ‘65 Mustang, 911, and Ford Escort mk1. An eclectic list!
For me, 4C will be difficult to replace: I love the brand and its history, and driving it is a special event - just sitting in the cabin and looking out through the curved screen is amazing. Being in it and driving it is like driving a cross between a 1960s or 70s sports racing car and a 1980s Group B rally car due to the turbo lag and engine characteristics, sitting low behind a great dash looking out over those curvaceous wings. Looking at the front corner from a low angle is IMHO the best viewpoint and very, very few cars look better. The steering feel is easily enhanced by increasing castor (which also makes the steering heavier when manoeuvring), though the suspension compliance is lousy over bumpy UK roads. In an attempt to resolve this mine is fitted with Tractive Suspension adaptive dampers, though this is a work in progress and we’re still some way from a solution.
So then, I’m an Alfa guy! Yesterday I called at my local Lotus dealer and tried a V6 and an AMG for short runs. My initial impressions are that ingress and egress is easier to the Lotus (in order of increasing difficulty it’s Emira, 4C, Elise). The interior is nice, but not special. The seats are designed for people with waist sizes larger than mine (I’m 6ft, 80kg) and didn’t hold me in place. The leather steering wheel was ok - but why can’t steering wheel’s be round anymore? The hints in the name, and Porsche seems to manage it. My experience of sitting in Emira was nice, but that I could be sitting in any modern saloon, just a bit smaller. Start up for the v6 was spectacular and I loved it! Conversely, the AMG was very ordinary. Surprisingly to me, the AMG felt faster than the V6. Manual or automatic is your personal decision. Both had Touring suspension yet the AMG had a firmer ride (only tested low speed, high frequency damping on well-surfaced roads) I was tempted to go with a V6 manual only to be told that production is to stop for 2 years. So I need to consider a used model or a new AMG automatic. Neither car felt special to me like the 4C does. However, Emira in either flavour is not doubt a much more accomplished driving experience in steering feel and ride. As this will be an occasional toy, a problem for me might be that that the driving experience is too anodyne. I wish it had tighter fitting seats, a proper round steering wheel, and adaptive dampers to provide a comfortable or more tightly-damped ride. Plan is to return and try a model with Sports suspension. Coming from 4C perhaps the firmer suspension settings will suit me better.
Anyway, hope this helps. I’m off for a spin in my Alfa!