I'd recommend a noise cancelling headset - once you have hearing loss you have it for life. What price will you put on keeping your hearing? What you save now you'll probably end up spending on hearing aids later.
I personally use the Sennheiser HMEC 25 KA - its not perfect but it does the job. I find the pressure around the ears can be mildly annoying after 2 to 3 hours but perhaps my headset / sunglasses are not that compatible.
The biggest differences I found were:
1. Clarity is much improved
2. The overall volume can be reduced significantly - I usually turn down receiver volume settings left by the previous pilot by approx 25%
3. The reduction in background noise is extremely good.