We are all aware of the Sigelei 100W Plus, it is superb, so lets see how the Arrow compares. I took the Sigelei as the benchmark and will list the pro's and con's.

Construction and Size
Physically the Arrow is only slightly bigger, the main difference is an extra 5.5mm in thickness and the Arrow is 62g heavier, that's because it's built like a tank, in the hand it just seem's a lot bigger than it actually is.

It's very solid and well built, very good finish, look's durable. I think the bigger feel is due to the box being very square and angular. Solid battery door and strong magnets. Internally batteries are a very tight fit and it does not come with a battery ribbon so removing batteries for charging is a pain, so I installed a ribbon by super glueing the end of a piece of ribbon into the inside of the electronics cover, works perfectly.

510 is fixed but juice well around the connector is recessed so every atty I've tried effectively sits flush.
Screen is a little bit slanted.

Buttons are lovely clicky buttons. You can lock the mod with 5 quick clicks and lock the wattage by pressing the up and down button at the same time. Screen dims after 15 seconds and sleeps after 1 minute and there is a very slight delay from wakeup to firing, but so minuscule I couldn't even measure it.
What I don't like is this 'close' symbol on the back, if you must put it there at least make it subtle, but to be honest, IMHO, if you need that sign you have no business messing with a 100W box mod.