Why plunge a router and then switch to a jigsaw to make a large circular hole in a sheet of plywood? Just move the router around instead.
You can use a bit that can follow a template to make this as accurate as you'd like, but freehand is usually sufficient.
Also: A notable omission in the "other powertools" section is the angle grinder. Both to "saw" a hole, and by attaching a drill chuck to the grinder. At that point it's basically an electric drill with another form factor.
You can splurge on router bits, but I've also got a set of perfectly usable 12mm bits from AliExpress that I've even used for hardwood, and which will be just fine for any plywood.
You can also spend a lot of money on drill bits if you're seeking perfection over the perfectly adequate.
As far as I can tell, router bits from AliExpress use the same sort of carbide as the 10-20x more expensive ones available from retail shops here in NZ, and they're cheap enough I wouldn't even consider having them sharpened. We're talking a few dollars for a straight bit, maybe low teens dollars for something fancier.
Never noticed vibration issues with router bits from AliExpress, though I do use a 1/2" router and don't tend to use huge bits so it would have to be pretty far out of whack to make a difference. Same for tolerance. That said, I also wouldn't reach for a power tool as the last step to a very nice surface finish or very high precision fit.
Carbide alloy quality is probably hard to tell by eye. Also hard to tell by eye, and a little scarier, is how well they're adhered to the bit head.
I also use cheap router bits on occasion, but the second one misbehaves even slightly I go ahead and buy an Amana or similarly high-end one, because obviously I've used it enough for it to be worth it.
I'm basing my statement on how the bits function in actual use; for me the cheapies are plenty adequate and the types I need are available, so far there's been no reason to consider buying high-end ones.
Yes, anecdote, but I also have some not-cheapies that came with used tools, inherited from woodworker family, etc. and so don't feel like this is a case where I just don't know what I'm missing. The volumes of work I do are way too small to justify a real comparison test, basically it's hobby stuff, but pros probably aren't going to be taking router bit advice on HN anyway...
Why plunge a router and then switch to a jigsaw to make a large circular hole in a sheet of plywood? Just move the router around instead.
You can use a bit that can follow a template to make this as accurate as you'd like, but freehand is usually sufficient.
Also: A notable omission in the "other powertools" section is the angle grinder. Both to "saw" a hole, and by attaching a drill chuck to the grinder. At that point it's basically an electric drill with another form factor.