Chainsaw Repair

Most everyone makes all chains 30-60 on the Oregon type grinders including me and I have no trouble.

I do use the 10 degree down angle on the chisel chains

Yes and I'm a firewood guy but might get roped into cutting most any type wood. I use mostly chisel chains but have some semi chisel that I use on the real dirty stuff.

Will the 30-60 combination be a bit more "aggressive" than the 25-60 or 25-55?

You need to match the power head, bar length, chain pitch and type, and angles to the task.  Changing angles alone will have some effect and some trade offs.

Guys who cut all softwood might sharpen at 35*, but this could bog down the same saw in hardwoods.  Hardwood guys might go for 25*. So the 30* 'default' angle is often used for mixed/all around cutting.

Similar thing with the 60* grinder head tilt (although Oregon seems to be specifying 55* on a lot of their chains in their 'Maintenance & Safety Manual'). More tilt might be more aggressive, if your saw can handle it, but may dull quicker too.

Philbert