Reach: This actually depends on you. If the topic further interests you, you will surely go to read more. And this is new, because the support page of advertising has been updated recently. I go through support pages after a certain period of time, and recently I found the ad control feature added at the end.
Plus, I think you need to concentrate on what you're saying. VIP hosted blogs and 50k pageviews blogs are totally different things. You don't get 50k impression a month doesn't mean nobody does. There are lots of hugely popular wordpress.com blogs which get over fifty thousands impressions a week. So, this feature is surely great for them.
On the other hand, VIP hosting is a paid upgrade what you need to pay for. For Ad Control, you don't have to pay any money. So why do you say about afford? If you can't afford VIP hosting, then you won't buy VIP hosting. But if you have a blog having over 50k pageviews per month, then you can put adsense and earn half of the total revenue.
Before writing, I get all the necessary researches done, so that nobody has to raise question on why I write.
Have a nice day.