I've been thinking about upgrading to a Screamin' Eagle intake and pipes. Has anyone done this and is the improvement worth the cost ? Thanks

 

On my 2010 FLSTC I just did the Stage 1 air filter, Rush slip-ons and download. Total cost was $635. A little more power, a LOT more and better sound, fuel mileage looks like it's going to increase a fair bit. Worth it? That's a personal call. For me it was.
That got rid of the cat and it no longer sounds like a honda : )

 

Properly tuned, it's one of the best bangs for your buck.
Emphasis on properly tuned.

 

You'd be better off spending your money on a power package from fuelmoto or going through Dr. V-twin. The SE slip ons don't have a real great sound in my opinion. For a little more than what the post above listed at $635, I got a SE intake, powercommander and a full exhaust....

 

There will be a definite improvement over stock. A proper dyno tune after the mods will improve it even more (but be sure to invest in a SEST for maximum benefit). Two-into-one pipes, if you feel like spending a little more, will really make things better.