I am trying to figure out if we can move our Angular 1 application to Angular 2. We have a sufficient amount of code to warrant using ng-upgrade as opposed to starting from scratch.
Our current application is pushing the performance limits of what Angular 1 is capable of. Hopefully Angular 2 will bring us some performance benefits.
My question is how much of an impact on performance our migration path will have (i.e. running Angular 1 alongside Angular 2 as per ng-upgrade guidelines)? Will it have a noticeable impact or will it not be noticeable in practice? My main concern during this period is run time speed as opposed to memory usage or load time.
Not sure if this thread is still relevant, I'll try to add some further notes. Currently we are at Angular 6, and the upgrade behavior has gotten a lot better.
For anyone having performance issues or thinking there might be issues I recommend have a look at the downgradeModule (https://angular.io/api/upgrade/static/downgradeModule#differences-with-upgrademodule)
You basically can either Upgrade the Angular 1 part or downgrade the Angular 2 part. On a first view they might seem similar but the behave fundamental differently. For anyone concerned with performance I definitely recommend the latter approach. This way you will have the improved performance for your new Angular 2 code and the old code runs at nearly the same/if not the same speed.
Even for fairly large applications it is a breeze and you very rarely have any performance problems.