Sell a few coins if you need/want to use the money right away (assuming you can't spend the coins directly instead), but you never, never go full fiat. That shit is dangerous man! It could be taken from you at any time, you can't move around with it, etc. Why would you want fiat??
More and more this is my thinking (and practice) too. Bitcoin is just much better to hold than fiat for so many reasons. After 3 years, I still get a thrill sending coins across the globe almost instantly with virtually no fee or controls. Yee Ha! That freedom is contagious and addictive. Once you get a taste of that fresh air, the fiat world of constraint and invasive body searches will never do again. And as you guys know, I'm not the only one who feels that way. Think there might be a few million (billion) others who feel similarly?
The idea that Hf suggests that $200 is expensive for bitcoins, is all a question of time frame. Yes, compared to last year $200 is outrageous. But compared to 2 years from now?? That is the question, and no arguing or insulting on these forums will answer that question. If you are short-term trader, looking to make a few fiat bucks here and there, and maybe buy a new car or townhouse, then maybe it is worth selling your coins now. It has been an amazing run. But if you are believer in the potential of this game-changing technology to make massive (even modest) impact on the financial system, and have the potential (granted, just the potential) to experience life-changing wealth, then do not sell your coins unless you absolutely have to. Pretty simple.
I love that line I saw somewhere on these forums...something like: "By the time I'm ready to sell my coins, I won't have to" Makes me smile, big.
Thought you guys might like this video, if you have not seen it.
http://www.finextra.com/Video/Video.aspx?videoid=513