ARK is fast, with 8 second block times transactions confirm quickly. One of the biggest issues I have with using crypto as a true currency is transaction time. Bitcoin can be slow, as can Ethereum, depending on how many kitties or lambos or whatever people are collecting today.
Lag inducing bastard.
There are some new super fast transaction currencies like Nano and IOTA but both of some issues currently. Mainly they are unproven at this point. IOTA you can watch transactions confirm and unconfirm in front of your eyes which is messed up and Nano still needs a decent amount of dev. Both are promising if they can get their kinks worked out and prove themselves but that is a hill they have only started climbing.
ARK is fast, while using proven blockchain tech while allowing you to stake without a wallet constantly online. Pretty cool, oh and it can be used for transactions because it's fast. SmartBridges, once implemented, allows you to trigger an event on one block chain from another, using ARK as the in-between.
Easy deploy side chains are coming for DAPP use. This would allow a company to create their own chain, and restrict use if desired. Or a DAPP like those kitty bastards to have their own chain so they don't clog up payments while also using ARK as the currency to make more of the bastards.
ARK offers a lot of advantages and I think it's one to watch in 2018. They haven't had a strong marketing presence, which can really hinder a crypto's growth, but they are working on that as well. With BTC volatility I'm not sure now is the time to be buying alts, since they usually increase when BTC goes sideways, but it's worth keeping your eye on these one for when a good alt run starts.