I've always been a big believer in using a clearing tank, and have enjoyed great success doing so. My beers are generally brilliantly clear, and I definitely prefer handing somebody a beautiful jewel-like glass of beer, with no cloudiness or haze. Furthermore, I've NEVER looked into a primary and thought "wow, that's ready to keg or bottle," even after 3-4 weeks! It always looked cloudy, with junk still floating on the top, and a good inch of easily roused trub at the bottom. OTOH, a day or two after racking off the trub, my beer already looks vastly improved, as though the very act of racking somehow caused stuff to drop out quicker.
With all this in mind, when I brewed my Kölsch in December, I decided to let it go longer in the primary than I ever had...just to see. To better visually gauge its progress, I used a 6 gallon better bottle instead of my usual buckets.
After two weeks: cloudy, with tons of junk still floating.
After three weeks: no apparent change...I'm not putting THAT in a keg!
After four weeks: this is getting discouraging...I'd better rack to secondary at the next opportunity.
So yesterday marked week five, give or take a day. I pulled the BB out of my chest freezer (65F w/Ranco) and was delighted to find STUNNINGLY CLEAR BEER! The yeast cake had settled down to practically nothing, and the surface was clean and devoid of floaties. The trub got stirred up a bit as I carried it to my kitchen, but quickly settled back down within a half hour. The small volume of sediment was shocking, I couldn't believe how compacted it was. I still had to use more care racking to my keg (sucked up a bit of trub, no big deal) but I managed. I even filled a small water bottle and chilled/force-carbed it: clear, beautiful and already quite delicious!
Anyhow, I'm not yet completely in the no-secondary camp. However, I'm now aware that it's certainly a viable option for me, at least for smaller beers. If I can come up with a better way of keeping cold break out of my fermenters (without sacrificing too much wort volume) I'm betting I can reduce the primary time, and perhaps give up secondaries altogether.