Just to chime in here, I have actually ridden scooters, e-skates, EUCs, and even owned an URB-E for a while. My goal was to find the most efficient and practical way to commute around a dense city (San Francisco). I have been using EUCs exclusively to commute for over a year now and have gone through 6 different ones trying to find the 'holy grail' EUC for commute purposes.
EUC's are the most compact shape that can be unobtrusively stored even when taking it in with you into crowded restaurants or bars, something that cannot be said of any of the other options. While scooters and the URB-E can fold, they are still quite tall which can be awkward sometimes. San Francisco has rampant bike theft all over the city so being able to take it in with me no matter where I am going was important. I can also take one with me in an uber, even if I don't have access to the trunk (as long as it isn't a Monster).
EUC's are in a grey area legally but in essentially all areas of the USA you won't be hassled riding one on a sidewalk as long as you are going slow enough (~10 mph). This is one area where they shine over the others. eskate and scooters don't have as tight a turning radius as an EUC so its easier to maneuver among pedestrians without them having to take special consideration for you. You also occupy the same amount of space as a pedestrian where your other choices are all longer which can annoy others if its crowded. If it gets *really* crowded you can always extend the trolly and walk it like luggage which everyone is mostly familiar with. Trying to carry a skateboard or push a folded scooter is generally more awkward. Eskate in particular (but also true to some extent for scooters and bikes) are generally either flatly illegal or heavily discouraged from being on the sidewalk. The ability to hop onto the sidewalk for sections of the commute when the street is too crazy is underrated.
EUC's have great range for their size/shape. Even what most on this forum consider mid-range boards in the 800-1000wh category can easily do most daily commutes without having any range anxiety.
EUC's handle rough terrain and large bumps better than any of the others due to the size of the wheel (this is somewhat rider skill dependant though).
EUC's have superior traction and handling in the rain compared to most other options short of a bicycle. This is most applicable in places like Seattle and San Francisco where it rains enough to be noticeable but its usually pretty light rain that is just enough to make everything wet but not enough to really be a serious storm or hinderance as long as your rideable can handle the now wet asphalt.
Practical considerations against EUCs -
Where I live broken glass is quite common on the ground on my commute path. Both on the sidewalk and in the bike lane/roads. Due to this I am always more stressed about flat tires than most. The small solid rubber tires on some scooters or the solid urethane wheels on eskates would probably have a longer average lifespan. This is specific to my situation though. I literally see broken glass every single time I ride more than half a mile in san francisco. Many scooters also can get flats though so this only applies as an advantage to some.
EUCs are inherently unstable. This means that in the event of any type of hardware malfunction you are probably going to be eating pavement. Hence the advice of everyone to wear protective gear. This is the only one of all the options where you could be doing everything correctly, be skilled, and have nobody near you and still fall and get injured. To be fair this is also a very rare occurrence. I personally have ridden 1000's of miles without it ever happening but just the tiny possibility that it could happen weighs heavier on most of the veteran riders minds than is fun.
They are addictive. Many consider this a plus but it is worth noting that I don't think I have seen many people just stick with the first wheel they bought for more than 1 year. So while on paper they are quite economical most people develop an itch for the latest and greatest *cough* @Marty Backe *cough*
Hopefully this helps, feel free to keep bouncing ideas here - the last advantage is the EUC community is probably the friendliest and close-knit of all the community forums around these devices. Good Luck, you'll have fun with whatever you choose I'm sure!