A hull tech will typically be mostly employed doing his or her job within his trade. (Ie, getting your Hep shots, cleaning the blackwater line out, welding up the pipe, building a new cabinet for the cave, etc)
An NET, particularly a (C) will spend more time doing stuff outside his trade specialty, but will be more broadly employable on the ship.
And, when an NET(C) is working, it's often in the Comm rooms (HFTR, SER, CCR, CER, Etc) and so kind of "out of sight" until something goes wrong.
With an HT, your workspaces would be literally anywhere and everywhere on the ship.
Both trades will work similar hours and duty watches when alongside, both stand engineering (MCR) watches.
At sea, the HT will typically be a "day worker" with occasional other responsibilities as Duty HT overnight, and DCC Watchkeeper. This could be short days if gear is working right, or long days if stuff is broken.
An NET(C) at sea will stand a 1 in 2 rotation, basically working 5 or 7 hour watches on a rotational basis (5 on 5 off, 7 on 7 off) so theoretically, you'd only work a 12 hour day, but it's usually longer, though the work is usually "cleaner" I guess. (electronics fixing vs mechanical/plumbing fixing)
I guess it comes down to your preference. An electronics tech will get a broad spectrum of training and experience, as will an HT, but in different areas.
Over to you, feel free to ask for more detail, or maybe I've already added too much.
NS