Speed is essential, in my opinion. My view is quite narrow, all those other systems and cryptos are too much to handle for me. Currently I focus on BTC, LTC, DGB, VERGE and NLG. And for the modern tech Steem (Golos), Bitshares and for the future EOS.
When projects are centralized closed sourced, or banks/government connected, I cast them aside right away. But that is my personal choice. The technology of iota seems quite interesting, yet I am short in time as it is, but hope to be able to dive into their whitepaper at a later stage.