I've been using a SWG in one form or another for about 4 years now. As with anything else, you must test your water. Those people that are having problems may not be keeping on top of their water chemistry. I have found that if you keep your levels at the recommended levels, you wont get corrosion, low chlorine production OR cell scaling issues. The listed problems all have to do with water chemistry being incorrect.
I LOVE my new CompuChlor unit that I have installed on my 33 ft round pool. my pool holds 25,600 gallons of water, and since this unit is an australian unit, it requires 5600 - 6000ppm of salt for my size pool. (that was about 26 bags of salt to lug) BUT....I was warned by pool stores and other SWG owners that I would get serious corrosion with salt levels that high. I have yet to see any sign of corrosion on anything. ALso, the best part of this unit, is it has reverse cell cleaning...meaning the unit actually reverses the polarity of the cell when it detects any sort of build up of any kind..and reverses it and after a couple hours of it running that way my plates in the cell are totally clean. I love it.
Anyway...if you want to quit lugging bleach, or chlorine to add to your pool...I highly suggest a SWG. You'll never be adding chlorine again. If you'd like to know more about my particular model, you can PM me and I'd be happy to share info with you. there are many SWG's on the market today that work well, I can only vouch for the one I have..but it has been "trouble free" since I powered it up.
Dan