I have used both of those methods when publishing... I do hesitate on the full article approach, but I don't run ads. (And to be clear, I do provide a whole-article feed)
One thing I don't like about the whole article RSS is that I get requests to narrate my whole website or blog experience, in addition to the normal writing about stuff.
In effect the full-article RSS audience has its own experiential needs, which include "tell me about what you added to the non-blog sections, tell me about the new tools in the sidebar, or the new article footer format, or even hey I never heard about the new design," and so on. Sometimes I also alter the CSS for a single post, when it makes sense.
Some of this narration is just expected if your main format is traditional, plain blog. But personally my blogs tend to evolve and incorporate other stuff. And for sites with even more of an experiential aspect than my own, I can see why RSS could drive the publishers a bit mad, increased exposure or no.
Because of this experience, personally I would rather try reading via a page-download tool or format, even automated w3m or something, and see if that's an improvement. You'd get the full article in plain text, but you'd also get some of the other stuff around the site, including links which you may even be able to mark for later download.