While you can make a tasty beer, I don't feel like the fake-lager-kolsch method makes something passable. It tastes like an ale and lacks that "lager character."
Contrary to popular belief, you can make lagers pretty quickly. Pitch low (46-48), ferment 48-52 until the beer shows signs of slowing down, then slowly rise up to 65-68. Allow some time for sulfur to blow off, and then you're good to go. I've make lagers in the 1.055 range that are in the keg in about 2.5 weeks. And I made a 1.080 maibock (FG 1.016) that was on tap in about 3.5 weeks. My expectation for finishing a lager is about double the amount of time it takes an ale of the same gravity.
Agreed. I haven't made many lagers yet, but...
In my limited experience, lagering does help make the beer a little cleaner and certainly helps with clarity soon/faster/better.
That said, if you simply brew with lager yeast at the appropriate temps...once it is bottled even without lagering, it tastes like lager. I've brewed several ales at hybrid temps (both notty and S05) and they might turn out pretty clean at lower temps (56-60F), they still taste like ales to me and not lagers.
Fun experiment if you really want to. Brew the exact same beer, split it between two carboys. Put something like Notty in one and a lager yeast (White labs Pilsner or similar) in the other. Ferment the Notty at 58, then 62, then 68. Ferment the Pilsner one at 48 and then a couple of days to clean up at 68 after all of the krausen has died away. Bottle half of each batch. Then lager BOTH beers for, say, a week at 36F. Then bottle the rest.
Try them. You'll find the differences interesting.
Also another fun experiment (if you can manage to wait that long). Stick a beer (any home brew) in the fridge and forget about it for a few months. Then crack it up. Short of a stout, you can read through the resulting beer (just visiting my in-laws and they had one of my APAs from this past summer in their garage fridge still. Opened it up, and damn man, that thing would ace the clean water act).