It's always the smiling, seemingly normal-looking, one's who turn out to be psychos. Talk about not judging a book by its cover.
Read the prospectus very carefully. Think about it. Then sit down and actually model different scenarios for yourself. I expect you may find this helpful. Be sure to include a variety of scenarios (including CHOPPY moves up or down).
Take a look at this article. Based on the article, Leverage ETF return can be estimated based on expected mean and variance. http://www.aaii.com/journal/article/leveraged-etfs-multiplying-by-the-unknown#box
I am thinking that 1x inverse etf like ticker "SH" is better than more leveraged, for whatever reason.