I'm an SL at an RG university. I got prompted because we have a yearly round of promotion rather than self-nomination and the powers that be decided I should be promoted. Obviously, I wasn't going to turn down a £8,000 pay rise 
I'm good at my job and I enjoy most of it.
But, I'm not looking to move up the career ladder any more. I'm happy to plod along where I am. I get excellent teaching scores and I'm okay at research (REF-able but I don't have thousands of 4* publications).
I'm also not "passionate" about the job. I like it but it's just a "job" to me. I don't work evenings or weekends regularly (will do if I'm under some pressure for a deadline) and I don't stress about work. If a great opportunity came up at similar levels of pay I'd think very seriously about it. I'm not "wedded" to academia and I don't see my identity as an "academic"- it's my job but not my whole identity, if that makes sense. As soon as I can, I'll retire from work and I won't look back. I don't want to be emeritus- I can't think of anything worse.
Sometimes I completely feel like the odd one out. I've never met anyone else in academia who feels this way (or at least no-one who's openly admitted it!). There must be people like me out there? Are there? Are you one of them?