If you can't charge at work, and can't charge at home (for example, if you park on the street and would have to run the electric cord across the sidewalk to charge your car), then you probably don't want the PHEV. Some of the Kia documentations suggests that it's bad for the PHEV's battery to drive it like an HEV and never bring it to a full charge. But if you can charge somewhere, then the PHEV might make sense for you. You get 26 miles (I think that's about 41 km?) based on electricity instead of gasoline for every day's drive, assuming you recharge at home every night. With the PHEV you're lugging around a heavier battery, which works against your overall efficiency to some extent, but you also have the advantage of a bit more horsepower when you need it on a long uphill drive (assuming you haven't fully depleted the PHEV's charge). It can also give you better efficiency in certain kinds of driving (for example, in stop and go driving, especially when the ICE hasn't warmed up yet, if you can do all that on the battery, you're likely to enjoy better overall efficiency).
I can drive my PHEV in EV mode on the highway up to about 75 MPH, but if you ask for quick acceleration, then the ICE will start in order to supplement available horsepower. I seem to get somewhat reduced electric range when driving at highway speed, but I haven't had enough opportunities to reach any firm conclusions about how big that reduced range is.
Depending on where you live, there might be other incentives, aside from the one you mentioned. In certain parts of the US you can get rebates from local governments for a PHEV, can also get a break on your electric bill for the portion that goes toward charging the PHEV (if you put in a separate meter, but in some places, you can get a discount for the cost of the new meter). In Southern California, I think there were either three or else four different incentive packages that I was able to take advantage of for my PHEV purchase (including the federal incentive).
I love my 2018 PHEV EX Premium, but my situation is somewhat atypical: I tend to do a lot of short all-electric drives because I work from home and don't have a daily commute; I have rooftop solar that generates a surplus of electricity (that I'm not getting much compensation for), so compared to what I was doing previously, most of my electric miles on the Niro PHEV are "free" (or nearly so).
2018 Niro PHEV Gravity Blue