Heated mats or heated propogator

Can I have some opinions please on whether heated mats as suggested by Monty Don or a heated propagator would be the better buy.

I think it also depends on how much stuff you need to put in it, and where it will go.

I have 2 heated windowsill propagators, which is fine for me, and means I can make the most of the available light. 

Now I've building my heated bench I think it's the best thing since sliced bread the polycarb cold frame I built to sit on top of it has made it even more useful - best of both worlds but as LilacSandy said - it cost me the best part of £100 to build.

I think it also depends on how much stuff you need to put in it, and where it will go.

I have 2 heated windowsill propagators, which is fine for me, and means I can make the most of the available light. 

same here, it means I can start stuff indoors while the greenhouse is still too cold.