Those strange naming choices definitely still have a cost but a lot of effort has been invested in documentation and alternatives to lessen their cost.

The mixed typing is... honestly, it's amazing. You really need to try it out for yourself in PHP7 or 8 - you can lean on really strict type checking in your application, go the old route or generally adhere to strict typing and relax that for entry points and library calls.

Lastly, PHP has come down hard and actually introduced backwards compatibility in a few key places to address some of the biggest WATs, I've been pretty impressed by the balance of the language stewardship.

It does definitely have warts, but there are warts on everything that people actually use in industry.