I too avoid added adapters if possible, however sometimes they're a necessary evil to achieve a desired means...
eGo to 510 adapters are the only way to run an EVOD (and a lot of other delivery devices) on a straight 510 threaded mod...
510 to 150 adapters are necessary in most cases to use a drip shield on a 510 atomizer...
On many if not most RBAs that tiny 510 connector is their Achilles heel!
On a straight 510 mod with no collar, an ego to 510 adapter with a beauty ring can not only improve the appearance but serve to add support and take some of the stress off of the connector.
There are many shades of grey in this black and white picture!