At my job we're starting to use angular as it helps us separate business logic from UI and even IO.
1. I would say no more than 2 hours at worse. The biggest issue for me is understanding the creation of methods for an object (I'm use to C# and Java, so JS is generally alien to me).
2. 1.5 - 2.
3. 2.5 once you have the core logic for your object models laid out.
4. Because it was what my employer mandated, unfortunately, I prefer Knockout but it all seems to the same in terms of end result. There's minor differences in terms of templating your pages such as for tabular data. The rest seems to be purely a matter of preference and familiarity.
1. I would say no more than 2 hours at worse. The biggest issue for me is understanding the creation of methods for an object (I'm use to C# and Java, so JS is generally alien to me).
2. 1.5 - 2.
3. 2.5 once you have the core logic for your object models laid out.
4. Because it was what my employer mandated, unfortunately, I prefer Knockout but it all seems to the same in terms of end result. There's minor differences in terms of templating your pages such as for tabular data. The rest seems to be purely a matter of preference and familiarity.