Ranked in these QuestionsQuestion Ranking
Full website with lots of content, info, users, comments, etc. Value for free.
Pro Filtering and sorting capabilities
The ability to filter by platform and license means that you can easily filter out software that you can't use. More specific filters and sort orders are also available.
Pro Easy to skim through content
AlternativeTo makes it easy to quickly find stuff. The lists are organized by likes which floats the best content to the top, and helpful tags warn you of undesirable attributes (such as the product being discontinued or if it includes bundleware).
Pro Better usability
Slant is really terrible by design.
Pro Shows all options
If you have a large list(~100) on slant only the first ~15 entries are displayed - even if you click see full list.
Pro Less manipulation
Less manipulation with guest/fake accounts.
Pro Tag based instead of individual Questions
It is tag based so there are less duplicates.
Pages load much faster and there is less annoying bling bling.
Pro Has a lot of information about products easily accessible
Con Limited details available on the site itself
AlternativeTo excels at showing you options, however it doesn't really tell you why one option is better/worse than another. It lists options by the number of likes it has received, but to directly compare the options is relatively hard to do.