For me, buying a straddle or strangle requires a low IV environment where the IV is likely to rise before the straddle nears expiration. Also, an environment where stocks are still moving but IV may be low due to "boring" markets and/or no fear in the markets.
I do think we may be at that point with many stocks. CLF would have been a good straddle a few weeks back as it was at $55 or so and climbed surely enough to $65 - the IV didn't rise though. I choose to do an RCC on it as I noted in another thread, but you can see the straddle part of the RCC was the profitable side. I have also seen for example GS rise from 155 to 175 so slowly and surely that no-one even seems to have noticed.
Personally, I doubt market IVs will remain this low for too long with items looming such as Financial earnings, Health care bill, any other business/political issue that may come up, etc.
Of course, you have to pick the correct straddle and manage your risk properly in any scenario.
JJacksET4