I'm actually a fan of rolling the paint. I usually go with an eggshell
or flat finish to hide any irregularities in the wall, the roller and
brush lines are much less obvious this way. I also have used a Wagner
once. I can't say it was horrible, but I don't know that I'd buy
another one. It worked well for painting the smooth metal surface of a
door where brush and roller marks WOULD have shown up very badly. It's
a royal pain to clean, and in order to clean it properly the unit has
to be almost completely disassembled. Spraying works well if you're in
a hurry and don't care about wasting paint with overspray.

Consider this, how many homes do you walk into and immediately think:
"WOW, what a crapload of roller marks! And just look at those brush
marks on the trim!"

A VERY bad paintjob might be noticeable, but most of the time people
don't see it beyond "oh, what a nice color".