First off let me say that I'm still learning about vaporizing, the effects, and Cannabis in general. I'm using it responsibly as a patient along the guidelines that my physician set for me. Due to me being a non-cigarette smoker he advised me to purchase a vaporizer, he even supplied me with a few distributor's info and discounts. What I know so far about vaporizers is what I've learned here at FC and from various internet sources like Wikipedia etc. the point I'm making is I don't consider myself an authoritative source on these matters, I'm learning just like you.
From what I understand combustion will release more cannabinoids, but in smaller amounts since some is lost in pyrolysis. On the other hand vaporizing can deliver more THC (the primary compound in Cannabis, it gets you high), but sometimes less of the other cannabinoids. However by vaporizing Cannabis at different temperatures one can target different cannabinoids and achieve the associated effect desired.
My vaporizer operates at a fixed temperature and I'm not sure exactly which cannabinoids I'm vaporizing besides the THC, I plan on researching that aspect of Purple Days vaporizer when I get a chance. One thing I can say for sure is this vaporizer gets me feeling higher than I ever did with smoking from any pipe, bong or joint. The high has always felt more uplifting, less foggy, and overall better for me. The highs with my vaporizer put me in a really positive mindset, more than I've gotten from smoking. I think this is due to the higher amounts of THC i'm inhaling with the vaporizer. THC is what you really are after if your looking to get high. Other compounds in Cannabis are better for things like appetite, pain relief and aiding nausea etc. At some point I think I'd like to invest in another vaporizer that is capable of different temperatures, that is if I find that the Purple Days isn't able to release certain cannabinoids. As far as I'm concerned i'd be completely happy only owning the Purple Days if it suits my needs. I don't collect vaporizers for the sake of having them, just as I never collected glass but I did have a solid, beautiful bong I was completely happy with. That's what I've found with my vaporizer. At my point in life I'm cutting away with material belongings that aren't necessary, so for me less is better.
It's all about finding what suits your needs and makes you happy. Keep asking questions, doing searches and educating yourself. Just being here puts you miles ahead of your buddies who only know Cannabis as something you torch with a Bic.
I apologize for the long post, I'm notorious for carrying-on like that.