Under what conditions would you eschew a CTL and use the Alternate?
When I miss the approach at the destination.
Was it fairly level terrain of mountainous?
Some of each over the years.
I was thinking I'd have much less problem doing a real-live min 600/1 1/2 CTL at let's say OXB than VVS -- and VVS is a home airport.
You'd have a
real problem with a 600-foot ceiling at VVS since the MDA is 673 HAA -- that's a miss for sure. OTOH, the circling mins for the RNAV(GPS) 2 at OXB are 469 HAT, giving you a bit of space to play with. Furthermore, when the weather's that low at OXB, it's usually due to an onshore wind, and landing straight in on 2 is not a bad idea in that case unless it's more southeasterly than NE/E.
And that would have the potential to be quite disorienting to hit the missed appropriately if you CTL and hit some cloud or obscuration at 600' AGL -- would be tense, for sure.
Well, with 131 feet to play with, it's not that hard to stay below the cloud while above MDA at OXB. OTOH, if the clouds are 70 feet below MDA, as they would be a VVS with a 600-foot ceiling, you're pretty much toast before you leave the IAF.
Look, I know you're pretty uncomfortable with CTL's. That's typical, especially for pilots today who are used to having a straight in approach to most any runway. There just isn't the emphasis on CTL in IR training that there used to be when we didn't have a GPS approach to each runway. Those of us who've been flying IFR for several decades had to learn them, and be able to fly them routinely, especially if we were hauling passengers who were paying to get to that location. If we CFI-I's spent more effort teaching circling techniques during IR training, I think a lot of the fear factor due to lack of familiarity/practice with CTL's would go away.
Now don't nobody get the wrong idea -- the risk factor goes up on CTL's, especially when visibility is down. As someone else noted above, I'd rather fly a CTL with the ceiling 100 above MDA but good visibility than with the visibility only a half mile above mins and the ceiling unlimited. It's something you must practice for and be comfortable with or you shouldn't try it for real. But as long as you learn it and practice it, it's another tool in the tool kit that may come in handy some day.