I never use a secondary vessel [anymore] for clearing the beer. Secondary fermentation is a misnomer. No fermentation should be expected in a secondary vessel when brewing beer. This may not be true when making wine.
I leave my beer in the primary for at least two and a half weeks, usually three. By that time the CO2 has off gassed allowing particles to drop out of suspension. The yeast/trub layer is compacted making siphoning over the top of it very easy. It is best to be holding the siphon for the final ounces of beer. Having the fermentor tilted decreases the surface area when nearing the bottom to get the maximum siphoned.
Every brewer has their own personal preference.
