It all depends on your cooking habits, is there a grill involved, do you Wok cook, is the range all gas or dual fuel,from the top of the range to the bottom of the hood what is the distance, is there a window in the kitchen that can open

Thanks for the follow up. There is a window in the kitchen that can open. The range top is a six burner gas Thermador and I while there is no grill involved, I do use a cast iron pan and a grill pan often. Its a 36" range top and a 36" hood, so capture is not ideal. Distance between them is yet to be nailed down. Thanks!

Rachel, Recirculating is a waste of a hood, It doesn't remove any heat from your kitchen and what grease it doesn't catch gets recirculated.
If it were me, I'd definetly vent to the outside.
Also be sure to use proper size ducting.
The larger the duct the quieter your hood will be.

Thats what I was thinking too, but wanted second opinions! Will 600CFM, if vented, be effective at all?

Yes, it is certainly worth venting. 600 CFM, vented, will serve most cooks and most kinds of cooking very, very well.

Yes, 600 CFMs is definitely worth venting. It's what many of us have over high BTU ranges. In fact, unless you have a grill or a very large range, you generally don't need more than 600 CFMs. With my 600 CFM hood the low speed is adequate for most things. I only use high when using my wok.

Thank you for all the helpful responses! I will go ahead and vent and overall, you made me feel much better about my (measly) 600 CFMs! Thanks!!!

600 cfm is definitely worth venting.

100 CFM is worth venting compared to recirculting in my opinion.

Yes, anything is worth venting.
Ductless hoods are simply ineffective at any cfm level.