In this phase, it's all about tokens capital gains. To this date I don't know about any token that would truly be a Utility token because a Utility token value is derived from its commercial value, as stated by SEC and others:
https://coinmarketfeed.com/regulations/wsgr-alert-icos-at-the-end-of-2017-what-we-think-we-know-and-what-we-dont-know-wilson-sonsini-goodrich-rosati/ (i.e. the platforms where those tokens could be spent are not operational yet, therefore they have no commercial value).
Basically, people hope for a high demand for the "utility" tokens in the future. If its corresponding platform would truly be successful, you might expect the token price to spike because a lot of people would need some. Since there is a limited number of tokens, their price will rise and they may provide gains never minding the fact they were called "utility" tokens. Regarding the token price on the open market, you can imagine the platform/service owner [or the market] would change the nominal fees based on the token value. So 1 token might be expensive, but you will only need a few subunits to pay for a service.
As I said, I don't see a big fundamental difference between the so-called utility or security tokens on the current market, concerning their possible gains. The most weight seem to me to be allocated within the actual feasibility of the endeavours that the distinct tokens aim to fund.