It's a tough one. Either it's worth the money to you or it's not. Performance wise, they're a great tool. If you’re just doing one project it might be a big investment, but there's always the option to sell a near new one to recoup some money.
One way to justify it (or not) is to calculate the difference in time it'll take manual versus automatic and multiply that against your hourly rate.
From my perspective, Ryobi and Makita are my brands of choice and I've been very pleased with the improvements in Ryobi products more recently - great value for money. - ProjectPete
Weighing up the pros and cons I reckon it will save time as well as using the right tool for the jobs concerned. You can't faff around trying to make do with the wrong tool and botching the job.
If you’re thinking battery versus air, keep in mind the extra cost of buying a compressor and hoses and finding storage for same. You also have the extra upkeep of maintaining the compressor and all the other stuff. Being able to just "charge and go" can be a much better proposition. - Henno
I have one of the Ryobi ONE+ nailers and it's a pretty good machine. Certainly good value for money. Being in the ONE+ ecosystem it does mean that you can then easily add more skins from the range. - Adam_W