I change them out every week. I have never put much thought into it being a pain in the ass or what not. I haven't really grown in soil, though, so maybe it's because I don't know any better. I have loved hydro because of the amount of oxygen you get to your roots, how easily you can adjust and maintain the ph and ppm levels, and you know what's going on with your roots all the time. Obviously there are more benefits/drawbacks to hydro, I'm just stating what I do, why I like it, and why it has worked out so well for me. Hope this helps with a little perspective.
edit - keep in mind, bubbleponics is just DWC with a drip feed system. Once the roots are submerged the drip is no longer necessary. One of the main things to consider is you CAN'T go overboard with your air pump/air stones. The more oxygen in each 5 gal bucket the better.
And about the stress, my plants never show symptoms or anything. I pick them up out of the 5 gallon bucket, put them in a bucket with tap water and a little h2o2. Clean their old bucket out thoroughly with h2o2 and hot water, fill with nutes/water, adjust ppm/ph, move plant back to that bucket and move on to the next plant.