going back to the original thread.....medium hot plug=Mccoy mc8 or mc9;odonnell 99; OS#8; Novarossi #5. Basically any plug thats numbered or rated as a medium heat plug. Some maybe medium cold and some medium hot as well. For an example, in the OS there's hot A3, medium #8, and cold A5 or very cold R5.
In terms of using 33% nitro, of course you get maximum power but at the possible cost of shorter engine life. I'd only recommend using that high nitro once you've already learnt how to properly tune & maintain an engine. You definately need to pay attention to your engine using that potent sort of fuel. Also most engines would require adding a shim to reduce the compression otherwise you again risk damage. And yes do not run in the engine on 33%. run it in on 20% and then re-tune it upto the 33%. Having said all that though, successfully running 33% would be really explosive power hey.
For me the best compromise is a high quality 25% nitro fuel where you get top performance and still retain engine life. Also nitro % isn't always a factor though. Good quality fuel ingredients go a long way to ensure the fuel is of the highest quality and this is quite often the difference between an average fuel and a high quaity fuel.
I suppose when it comes down to it, its a personal choice in the end.