I have found that if you write a mix of both info hubs and product hubs in the same niche you can do very well. I think nowadays it can be very hard to get traction in search for a product focused HP account, but when a few good quality product hubs are within the same niche as your strong/great quality info hubs they can get good rankings. It's all about building account authority with Google.
You can also funnel some traffic from your info hubs to your product hubs when the products are highly relevant to your audience (in the same niche).
One thing I would also suggest (I saw your question in the forum today) is that you try out 3 or 4 different niches. Commit to writing say 6-10 hubs in each niche. That way, over time, you'll get a good idea of what niches attract the best/most frequent buyers. In my experience, some are much better than others in terms of conversions.
Steer well away from books, CD's, computer games and DVD's as they just don't seem to convert very well at all!
So.....I really wouldn't see it as an either/or type question, more of a, "how can I make both of these types of hubs work for me?"