Is anyone using installment warrants as part of medium/long-term investment strategy?

If so, what type of warrants do you use?

Self-funding, rolling or endowment warrants ?

American or European style?

What types of stocks do you buy them against?

What sort of gearing level do you use?

What is your strategic approach when investing in warrants with a medium/long-term time frame?

Which issuer do you use?

What sort of interest rates do you pay on the loans (is it a variable or fixed rate)?

I am mainly looking at these as a way to generate extra income in a long-term investment portfolio.