Half ton trucks and 3/4 ton trucks are a total misnomer these days. Back in the old days, half ton truck meant 1,000 lbs in the bed. Nowadays you can easily configure almost any truck from the majors to carry upwards of 2-3K lbs payload and towing capacity up in the 12-13K lbs range. A properly configured 1/2 ton truck is just as capable as any 3/4 ton truck or fairly close anyways.
The real difference between the trucks is that the 3/4 ton will be much more able to take the abuse of the job site, towing daily, hauling daily, etc. Next time you get a chance take a look under the truck between a 150/250. The 250 will always be much more beefier, bigger brakes, bigger axles, etc. It also will almost always ride much rougher, especially unloaded. Load em up, some can ride decent.
FWIW the EV-150 is a heavy beast as well.