Is there any difference on performance when choosing DISTINCT or GROUP BY to bring distinct values?
The two queries are functionally identical so should perform the same and as you can see from the query plans SQL server has indeed spotted that there is no difference between the two.

Of course as soon as you need to perform and aggregate operations you need to use grouping instead, otherwise you'll end up having to use the "distinct" version as a derived table and joining for the other detail which is not going to be the efficient way around.