I was a surface ELT, just got out a little over a year ago. I'd say it's just about all benefits going ELT, you'll qualify mechanic watchstations anyway and can stand those watches and your senior in rate is going to be the same as a mechanics as well, meaning your resume is going to look the same with the exception of the ton more stuff ELTs can add to it as well. Obviously it depends on what you're planning on doing afterwards, but while I was job searching I was perfectly qualified for mechanic related positions but ended up being found by Newport News shipyard for a radcon tech, it was ok and paid really well but a little stressful so I ended up moving to the chemistry lab recently and I love it. Another ELT from my ship came to work here around the same time but went to engineering and writes work packages and procedures, working with mechanics, but he got the job because they know ELT is a demanding attention to detail oriented rate plus he was chief reactor watch (mechanic senior watch) qualified so like I said being an ELT is just more icing.
All that being said, ETs and ELTs are easily the most scrutinized and stressful nuke rates, and they both determine the largest portions of ORSE scores because of their importance, so it's very demanding at times. In RM/RP (reactor mechanical/ reactor propulsion) there's a lot of mechanics and it's easier to coast by and just do your time and get out if that's what you want, in RL (reactor laboratories)there's only 20 or so ELTs and there's a lot more pressure on each person. I personally miss that pressure, it kept you on point and it's harder to become complacent, but I knew a few guys who didn't like it and ended up leaving RL to go to RM.
As far as becoming an ELT, they say grades matter and they're probably important but honestly if you just hang out with the ELTs and make it known you're interested in being and ELT, you'll have a good shot, they choose who gets in and when I was in ELT school we saw all the time when they would deliberately deny people who were assholes or whatnot for the next upcoming class. I was an average student but super quiet and when I got to prototype I got a long really well with the ELTs on our crew, I wasn't even planning on being an ELT but then they recommended me and I got in without even putting in a package myself.