CPU ratio dynamic mode. Are there any negatives?

I have a bit of a noobish question despite not being all that noobish.

I've just built a new system and this is my first time with an unlocked CPU (i7 4770k.) I had my previous i7-930 OC'd to 4.0 but with everything fixed. At the time I built it the conventional wisdom was that it would mess with your OC if you enabled turbo...true or not, I left it fixed.

But now with my new Haswell and new MB (MSI Z87-GD65) I've set the CPU ratio to adaptive with my mild 4.2 GHz OC (running 100% fine with stress tests maxing the temp @ 60 C.) This means that my CPU is underclocking itself to 800 Mhz when doing light tasks like simple web browsing etc., and immediately going up to 4.2 GHz on demand when needed. I've run 3DMark 11 with it locked and in dynamic mode and I get identical results...so I know it's ramping up when needed.

Like I said, everything is working just great and this seems like a wonderful "best of both worlds" set-up to me. But I assume some of you who have already worked with unlocked CPUs may have done this in the past and have some experience with multipliers ranging from 8-42 or similar.

Is there anything I need to watch out for?