The problem is in not knowing what "down" means.

Upside down = base up.

Anyhoo, CFLs vary widely by brand and even by model for warm-up time.
I have some LOAs and Feit Electrics that come on full intensity, and
some of the same brand (earlier production?) that take a bit to
brighten up. I have some vanity-globe style Sylvanias in the bathroom
that are nightlight-bright for about 10 seconds and take another 30
seconds to come up full brightness -- very annoying, especially since
the globe-style are so much more expensive than a plain spiral. I also
have a GE that has a totally dark delay, then comes on, which annoys
me more than the Sylvanias.

My advice is, try different brands until you find one that you like.
Kind of expensive way to go about it, though. I wish these things were
rated on the package with the time it takes to go, from off at 72*F,
to 80% of full rated brightness.