Last few weeks I saw the sudden and big rise of the values of every coins no matter who are developers. That happened after the previous longer term big dump. Price is of the most importance for me.
If you're doing pure speculation, price / market cap are key indicators. If you're trying to make a long term bet on an Alt coin that has mainstream potential I believe you need a solid team, solid backers, and technological advances that make the coin more attractive than others.