As your last thread about this, well replacement for the 4%, got at...you want the Next%. It's going to feel the most "right" after coming from the 4% and be much more versatile for you.
The Alphafly is a good shoe but if you've never run in anything as bulky or high stack it's going to feel extremely strange. Also the Alphafly 2 will be coming out in a few months and by all accounts it looks like a FAR better shoe, solving some of the primary issues the OG had.
Trust me, you want the Next%2. It's the current benchmark for carbon plated shoes. You'll want to have run and raced in it. In the sprint with the AF2 comes out and some of Nike's next gen racers you'll have a baseline to gauge their performance like you currently use the 4%.