Yes, it's brilliant and I love doing it.
BUT, it's not for everyone by any means.
To put some context on my view, I've being doing it for teens of years and have getting on for seven thousand hours instructing. All at flying club level, teaching for the N/PPL, Night and IMCr, with a few seasons of MoD Flying Scholarships in the early years.
I've never done it full-time, typically I'll fly about 3 days a week and have always had a "proper", non-aviation job to pay the bills. As you seem to be aware and will now be told repeatedly, there's not much money in it.
That could be why I still enjoy it, as I've got the normal job as a comparison, so flying has never become the mundane, day-in, day-out slog.
PPL instructing is at least as much about the personalities of your individual students, as it is about the flying. It's challenging, immensely rewarding and sometimes sooo frustrating.
I've always shyed away from doing any more "advanced" instructing, such as for the CPL, especially not for an integrated provider, that just doesn't appeal to me. It's too standardised and structured for me I think, you won't get to develop the relationships with students you get at a flying school. Although I occasionally think that doing the FIC might be interesting.
You as an individual FI, have a huge effect on what kind of PPLs we end up with, your attitude rubs off on them. It's too easy to teach down to the minimum syllabus requirements, how often do we come across PPLs who've never sideslipped, or operated from grass. Their only experience of simulated emergencies are the obligatory EFATO and PFL, even for those, they new they were going to be happening that flight. I would so love the ability to be able to "fail" all kinds of systems and controls, to be designed into training aircraft.
Being an FI is as good a job as you choose to make it, introduce variety and challenges into your lessons, don't be constrained by the standard hour in the LFA and X/C to the nearest two airfields. Most students will be up for doing some more interesting stuff, take them away for a whole or half day, show them what they can do once qualified. Even trial lessons can be fun, you will get some that are just a PITA, but on the whole, they're excited and enthused to be there. I've got little time for instructors that moan about TLs, they're your shop window in effect and we should be sending our customers away happy, so they'll tell everyone they know how good it was.
If you do decide to go ahead, I suspect you'll pick-up a job pretty quickly, your CV would standout from the 200 hour heroes (no offence), who having thrown £80k at OAA or somewhere, then decide that actually, they've always wanted to be an FI
. or at least it would if it dropped into my inbox/letterbox.