My advice would be to have a couple of spindle gouges. One being a deep flute with a fingernail grind. Another like you have which probably has a shallower flute and a less acute grind. To briefly explain the difference a shallow flute has more meat left on the tool under the cutting edge so is more sturdy when taking cuts that go deeper into the workpiece. You can perform more fine detail work as a result. But these shallow flutes don’t really favour fingernail grinds so much, but you can get a swept back grind if you need to get into tighter areas.
Generally the fingernail grind suits a deeper flute and is slightly more versatile for beginners, but can create more chatter if taking deeper cuts as there’s less material on the tool.
There is a whole science and entire books on this topic, and some very experienced folk on here, but I think most would agree that a selection of options, built up over time, is the way to go. You’ll find your favourites and naturally reach for them after a bit of practice. You may even end up with your own grinds depending on how you sharpen your tools. It’s fun to experiment a little too.
Cheers
Ash