Question
Pro's and con's of pruning with gas powered shears vs hand shears?

Splintered ends vs clean cut?

Answer
Thomas:

Personally, I use pruners for almost everything.  I have no disciplined hedges.

Shears of any kind will not make absolutely clean cuts.

If you have a hedge, then pruning will take forever.  Hedge plants, for the most part, are fast growers and tolerant of "split ends."  Which type, hand or machine, will depend on if you like excercise or want a job done quickly.

If, on the other hand, you have a rare shrub hedge, consider pruning it.

Hope this helps.  Best wishes.