As a 5th-gen (VTEC) VFR800 owner, I'd honestly suspect you'll be disappointed after the S1K. I've always liked Hondas but the VFR8 disappoints in some areas- build quality isn't great. Regulator/rectifiers will die. You will need to replace both camchain tensioners every 20-30,000 miles, the stator will probably burn out and will need rewinding.
Throttle response was improved from 2004 onwards, but it's still rubbish. Often very hard to hold any revs below 5000rpm.
In town traffic if you have the headlights on and the cooling fan kicks in (and it will, a lot, since the side-mounted radiators don't flow any air) you may find the battery running flat as the generator can't really provide enough juice to keep everything running. This is worse if your reg/stator are borderline.
The bike is rife with poor design- the fairing is a 3D puzzle and virtually every fastener is different, the fan blows the wrong way as Honda didn't want to expel air in the rider's face, so you often find yourself in the odd situation where you're riding at 30mph but the bike isn't cooling down as the fan is opposing the airflow. Doh. A VTR1000 fan fixes it, but you shouldn't need to.
Don't get me wrong, I love my VFR, have had it the longest of any bike I've owned, and when it's on song it's a good ride. It even wheelies well and the VTEC nois is addictive even if it doesn't really add anything, but given what I know now I'd hesitate to buy another. 4th gen is more sorted, has gear driven cams so sounds like a VFR should, but has no ABS if that bothers you. Newest VFR8 is supposedly much improved, but still mega money. I'm tempted by a VFR1200 though- generally sorted, reliable bike with a peachy motor, lots around within your budget.
NC750 is the equivalent of a diesel bike- torquey but runs out of puff at bugger all revs. CB1000F is supposedly a brilliantly capable bike, torquey and fun, dirt cheap, but the looks are just so plain and "Meh". I was on the verge of getting one, figuring you can't see it while you're riding, but bailed.
Never ridden a Z1000SX, would like to, but they just look so wide and unwieldy.
MT-07 cheap laughs but a bit wheezy, especially after the S1K. MT-09 is definitely your friend!
I'm considering replacing the VFR8, have thought about MT-09s, but am leaning towards the KTM990SM-T at the moment- mad motor with practicality built in and great build quality. Prices becoming pretty affordable and might drop a bit further now the replacement 1290SM is incoming....