Glow plugs: Turbo vs. normal
 

My .12 engines in use at the moment:

NR NS12-S5 Turbo plug and NR RS12-S3 M Rossi with normal plug. Both engines with same amount of runtime on them.

My experience:
Both engines very strong! The NS12-S5 is stronger but very very moody (turbo) I need to have the tuning screwdriver and temp gun at hand all the time. I have to re-tune it every day. Very narrow glow plug temp range

The RS12-S3 (normal plug) is so much consistent! It starts in a snap, it keeps temps more even. Its not so sensitive to weather changes. Wider, more permissive glow plug temp range

I'm even thinking at fitting a normal plug/button to the NS12 S5...

Ok, I'm not a tuning expert. This is just MY OWN personal experience.

What are your experiences with these 2 types of plugs??

Personally, I prefer the turbo plugs. To me, they keep better tune and give better performance.

You can try switching to a normal plug, but I think you probably have other issues with the engine. Possibly an air leak, wrong plug for fuel & atmosphere you're running in, or simply not tuned right. Turbo plugs do have a slightly narrower "sweet spot", but not so much as to make it difficult to tune.

Edit: Just noticed you're form DC. Get one of the experienced local guys (Eric Jones, Nigel, Jason Miller, Arvin, etc) to look at your engine. If they can't get it tuned, it never will.

You've got 2 different engines there, so I don't think it's good assumption to base tubro vs. normal plugs from how each of the engines run b/c turbo plig is in engine with more ports and sometimes more ports describes the problems you have. Also if running too cold of a plug tuning window can be small too. So I'd prolly try next hotter turbo plug out on the 5 port motor and see if it runs same, better, or worse, then see if the button from 5 port motor will fit into 3 port motor. Then try whichever turbo plugs was best out in the 3 port motor, that way will get you a more definitive answer as to if you are seeing different results from each type of plug body.