What I constantly ran into was disconnecting from the server I was connected to and wrangler not being able to handle that. At the time I had a somewhat spotty connection (nothing terrible), but it made wrangler dev very painful - so much so that I ended up writing my own node.js wrapper around it for local development. The lock-in to webpack also isn't great when I am nowadays accustomed to esbuild which is so much faster.
Ohhh I remember this too, I hated how it consistently dropped connections. A community member fixed this for us (here https://github.com/cloudflare/wrangler/pull/2008) so that it transparently and automatically reconnects now and the experience has gotten so much better.
And of course, miniflare reduces even the chance of that to zero :)
We also don't have a lockin to webpack anymore (you can choose custom builds with the "javascript" type, which I admit is a little confusing). We're going to move away from even this dependency and make everything much faster and lighter, stay tuned.
I've faced this too, where you'll save, then hit refresh, and it show the previous version; despite the fact that we "know" that the code is changed. SO we should be able to queue requests when we have a new version uploading (and of course, make the whole thing faster). Thanks for your feedback!
Happy to see miniflare now :)