Slow toilet; drain or vent?
The other toilets in the house function normally; so it's not the horizontal sewer line in the basement. The other fixtures near the problem toilet (shower & double sink vanity) function normally - with the exception that I've caught an occasional whiff of sewer gas from the sink drain right after flushing the toilet.
I've got a bunch of vent stacks in the roof. Near as I can tell, there's one that serves only this toilet and the double-sink vanity. The shower seems to have its own vent, as do the other bathrooms, kitchen and laundry.
I'm inclined to suspect the vent. Can an obstructed vent slow a toilet like this? Is there a way to check it, or some kind of other indication I should be looking for?