Mezz Debt & Capital Structure

Is it possible that they were issued at different times? The senior debt could be old and the mezz could be issued later when the company had more stable cash flows and a greater margin of safety.

Seriously? Have you given any thought to the fact that risk-free rates are close to 0% now and was ~5% in 2006-07? I'm willing to bet Mezz 1 was issued in the past 18 months and the senior debt was issued 4 years ago.

do you have any info on the equity pieces that came with the mezz?

Maybe Mezz 1 has more favorable convertability features than Mezz 2 and 3....also sub debt may be higher in the capital structure but has no upside other than a high IR and both typically share same risk as nothing will be left most likely in bankruptcy scenario as senior debt will most likely wipe it all out. Also could be what milkman said....

As pointed out, the interest rate doesn't necessarily fully describe the cost of the capital. Additionally, you haven't mentioned the current market yields on the senior tranches. A bond could easily have been issued with a coupon of, say, 10% a couple years ago but be trading today in the 6-7% range.

Did you look at what the PIK component of the deal was? what percentage of the equity they can participate in when the term closes? you have too look into the subordinated docs it's really not as simple as just looking at the rate of cash interest bieng applied to principal.