Regular Ballast vs Digital Ballast?

I am looking to buy a new HPS, my question is are the digital ballasts worth the extra price over a normal ballast? I have heard the digital ones are much quieter. is it worth it to go digital?

My 2 Choices:
Regular Ballast

Digital Ballast

Which to choose? I am on a slight budget but i can spend the extra if needed but would prefer to be cheaper.

Thanks!

digis are cool,quiet and cheaper to run and weigh far less

the extra cost will pay for itself by the saved energy and extra light, plus you can run a MH bulb in them (if it's a switchable ballast)
The only negative is they can cause radio interferance in some models.