You are absolutely right, of course... :-)
In fact, I'm not searching sharpness "per se", and many great pictures aren't that sharp anyhow!
Let's say it's a by product of testing MF and AF (hyperfocal and al)... The 50 is short, hassle free, and cheap (It can take some beating), while the 180 needs the two hands, a bit of thinking and some good positioning :-)

I'm a bit on the "longer" side of focal lengths (even in film days), the 85/2 AI is for me the everyday strolling lens (even for architecture), the 50 is really great, but I feel I would like to try in the 105/135 department...
Those two focals are in DC or micro (for the 105). The DC is for "defocusing" in portraits (I used nylons on enlarger's lenses in old times ;-) ), so the micro/macro one is very tempting.
The 105/1.8 AIS seems the good size to keep in a (big pocket), it's MF.
The latest 105 ED VR is really big but looks like a superb lens (In Whales).
If I find a cheap and clean 105 AIS I might give it a try, if not... I'll break the Piggy Bank and get the Macro VR one for Father's day :-)

As a side note I usually find myself agreeing with Bjørn Rørslett quite often...!

When I'll win loto, I'll get the 85 PC :-)

"What can I do, What can I write, Against the fall of Night". A.E. Housman