People compare these two technologies, and it seems an established fact is that Angular is evolutionally more advanced framework. We're not going to contradict, contrary, we agree with it, but it's better for an opinion to be grounded on facts that one can evaluate and verify.

Fortunately we got a chance to make such a comparison.

We support conversions of Cool:GEN (a legacy CASE tool with roots in 80th) to java or C#. In its time Cool:GEN allowed to greatly automate enterprise development using Mainframes as a server side and Mainframe terminals or Win32 GUIs as clients.

The legacy of this tool are probably hundreds of business and database models, milions of programs generated on COBOL on Mainframes and on C or Java on Windows and Linux. All this runs to this time in many econimic sectors.

Usually the client is some enterprise that invested a lot into design, development and support of their business model using Cool:GEN but now most such clients a trying not to lose this legacy but to convert it into something that goes in parallel with todays technologies.

As original technology is sound, so it is possible to map it to todays Java or C# on server, REST or SOAP as a transport, and Angular, AngularJS or some other on client. Such automatic conversion is an essense of our conversions efforts.

To understand a scope consider a typical enterprise client that has 2-3 thousand windows that are backed by 20-30 thousand programs.

Now, consider that the conversion is done. On output among other things we produce a clean java or C# web application with REST and SOAP interface, and Angular or AngularJS web client that encapsulates those 2-3 thousand windows.

Each window definition is rather small 5-10 KB in html form, but whole mass of windows takes 10-30 MB, which is not small any more.

For AngularJS we generate just those html templates, but for Angular we need to generate separate components for each window that includes typescript class, template and style.

While amout of generated resource for AngularJS stays in those 10-30 MB, generated Angular takes at least 5-10 MB more.

The next step is build.

AngularJS builds distribution that includes all used libraries and a set of templates, and it takes something like a minute from the CPU. Produced output is about 300 KB minified script and those 10-30 MB of templates (multiple files with 5-10 KB each one).

Angular (here we talk about version 9) builds distribution that includes all used libraries and a set of compiled components that are to be loaded lazily on demand. Without of the both angular builder that performs tree shaking build takes days. With tree shaking off it takes 40 minutes. This is the first notable difference. Produced output for ES2015 (latest javascript) is about 1 MB, and 15-100 KB per each compiled component. This is the second notable difference that already impacts end user rather than developer.

The third difference is in the end user experience. Though we have built equalvalent Angular and AngularJS frontend we observe load time of angular is higher. This cannot only be ascribed to bigger file sizes. It seems internal initialization also takes more time for Angular.

So, our experience in this particular test shows that Angular has more room to improve. In particular: compile time, bundle size, runtime speed and simplicity of dynamic loading (we have strong cases when template compilation is not the best approach).