“ benefits of ” vs. “ benefits to”

I encountered an expression:

key benefits to using [something]

To my mind the version below would sound more natural:

key benefits of using [something]

Are both versions correct? Is there any difference in meaning?

Well, both do seem to be used, with benefits of being more common than benefits to, and apparently always has been.

You might also compare actual published instances of benefits to using versus those of benefits of using to see whether you can pull out any major nuance.

However, I think you probably want benefit of here. The OED has this to say about it:

3. a. Advantage, profit, good. (The ordinary sense.) for the benefit of: for the advantage of, on behalf of. to take benefit of (a thing): to take advantage of, avail oneself of. benefit of the doubt: see doubt sb.

Thinking about the difference between:

• a benefit to the community
• a benefit of the community
• a benefit for the community
• a benefit from the community

It seems like to and of go different directions. A benefit to society is different from enjoying the benefit of society. Similarly, benefit of clergy and benefit to clergy are quite different.

But I also think you are right that some people may use this interchangeably; I do not find anything wrong with either of your two formulations, but if push came to shove, I’d likely opt for the of version.