WP RSS Aggregator is way more well supported as there is a dedicated team working on it, their support is amazing. Also there are more features in that plugin (considering the add-ons) than Autoblog has. The Feed to Post add-on is probably the most advanced out there in terms of how well it imports into WordPress posts or other custom post types. It also allows you to import full content from feeds even if they only provide an excerpt.
Pricing wise WP RSS Aggregator is way cheaper ($67 for the Feed to Post add-on) when you consider that its license is for one year, while with Autoblog you pay $19 per month = $228. Hope that helps.