I've never done side by side comparison, so I look forward to the final results of Philo's test - keep us posted, I'll subscribe to this thread.
But, I have been totally happy with my results (trimming). When I do miss a lower branch in my pruning, I find that what comes of it is hardly worth having around (a bunch of pain in the ass popcorn).
As far as stress goes... I'm sure there is SOME stress, but it doesn't seem to be enough to notice IMO. My plants keep going crazy with new growth immediately. I prune pretty hard. Every time, I get done and think 'what have I done?' - they look a bit butchered. But VERY quickly they fill back in, and look better than ever. I've noticed yield and quality get better as I get better at pruning and anticipating how they're going to grow after the pruning.
Not saying that everyone should do it my way... do what works for you. But I've seen good results.