This answer will change drastically depending on your line of work but for me I can have the all in one unit solution a then if i need to expand i can put a mixer in front to interface with it as a recorder.
I haven’t had much real world experience with them but i think for the price I would air more on the side of investing the the Sennheiser G3 set. For the expense and amount of uses from them I don’t think that much of them.
I answer this question by the economics of the content basically. Commercials pay more because the upside of the piece of content is much greater than the cost of it. If you do a worldwide commercial for a popular brand then they are going to make, realistically, a ridiculous multiple on the amount spent on the commercial, even if they go 2 days into overtime for everyone. Also the complexity of these projects is usually higher.
The video below will automatically skip you to the right section of the video bit essentially it’s a 2 part answer to recording sound FX on the fly while doing location sound work: