I've owned two VFR750's over a couple of years and zero 1150GS so far, but I have ridden the 1150 both on-road and off, and I've also ridden an earlier VFR800. My usage profile is (or was) very similar to yours.
The VFR has become increasingly bland as it has developed, and the 800 I rode was anodyne, but very, very efficient. I'm told that the latest VFR has some character designed back in courtesy of the new variable valve timing widgetry. However, the latest one won't have the trademark rattle of the valve geartrain - they've gone back to chain driven cams.
There many people here who can discuss the features and foibles of the GS.
I'd suggest that head to head, if you can only have the one bike, for work rest or play, you'd want the VFR. Both will do the job fine, but...
1. Both bikes are well built, but VFR build quality is (or was) unsurpassed. My two used to live outside and be ridden all year round in the foulest conditions; I used to jetwash them once a year in the spring and get the brakes de-gunked, and they came up looking like new; a Suzuki would have turned into a fused lump of ferrous oxide under the same treatment! GS seem to suffer from the odd Friday afternoon syndrome bike, based on a representative sample of my friends who have bought and owned them, and some of the minor detailing can be less impervious to the tredations of the weather than might seem perfectly desirable.
2. You can do track days on a GS, but the track is not its natural environment, the tyres aren't really up to it and anybody trying to help you (instructors etc) is likely to be riding a sports bike, which makes things tricky. Oh, and if you get your knee down on a GS, the ambulances will already be rolling...
3. On the motorway, once you've pissed around with different screens and whatnot (true of both bikes), the VFR will give you significantly better wind and weather protection. The GS should in theory be more comfortable, but I did something over 60,000 miles folded onto two VFRs and a Sprint ST, and comfort never bothered me, so don't be too concerned. Engine wise, the motorway is where the limitation of a 'mere' 85bhp shows up most obviously. The GS is at its best on goat tracks, poor surfaces and twisty B Roads, especially those with hedges, when it is likely to be faster point to point than a sane man on a 600cc sports bike, due to the equally superb handling coupled with being able to see over the hedges/where the road goes better. On fast A roads I guess the VFR has an advantage, but only when making significant progress your honour.
4. You can't take a VFR offroad, but then truth be told you probably wouldn't really want to take the GS offroad except once, to prove that you could. Like the BMW X5, it isn't really going to be first choice for a weekend of mud-plugging. If you want to ride offroad, my suggestion is
go and do the BMW offroad course, marvel at what the GS can do in the hands of a Paris Dakar god (Simon Pavey), and then go out and buy yourself a decent small trailie and use that for green-laning.
5. Even muted, the V4 makes a lovely noise, and has buckets of smooth, creamy torque on hand, whereas the GS sounds almost literally like a fart in a beancan as standard, and runs out of puff as the revs rise. It's down on power and up on weight which also doesn't help in the civilised power delivery stakes. Oh and the vibes on the boxer piss some people off more than others. You can make both bikes sound wonderful with some tasteful aftermarket cannery, the GS improving immeasurably under the influence of a Remus end can and some other pipework changes.
6. The GS is imposing as hell, but also at least as f.ugly as anything on the road today. The VFR is less imposing but quite attractive. This one is a tad subjective...
7. Residuals. GS don't depreciate, or at least they didn't until BMW released a new, improved GS. Expect prices to drop rapidly in the short term, so buying an 1150 in the next 4-6 months might be a bad move. VFRs don't depreciate much either...
8. Service. Honda dealers are more common, and more variable in quality. Find a good one and you are sorted. Many BMW dealers appear very often convinced that they're doing you a real favour taking your money.
9. Round town, the GS rules. The VFR isn't
bad but the GS is great.
10. Supply. The R1150GS may yet come into glut as the 1200 has launched, but for too long it has been 'I can get you one for June if you don't mind Yellow', a fact which surely explains both point 8 above, and the paucity of discounts offered. In contrast, the VFR is usually available in the colour first thought of, from stock, and discounts can presumably be found!
So, if you do a lot of motorway miles, and fancy doing a few track days and race schools as diversions from your travels, then you want the VFR. If you only use the motorway because there isn't a more interesting alternative, have a pot of cash to hand, spend extended periods negotiating Kew Bridge & Hyde Park corner and either never want to do a track day or have a pucka sports bike tucked in the back of the garage already, buy the GS.
Alternative suggestion: Buy an Aprilia Capo-Nord (Aprilias giant trailie, nobody bought them despite there being not a lot wrong with them, so you can buy them brand new for about £5,000), and a used Triumph TT600 (a very untrendy but brilliant handling sportsbike, again poor residuals mean its cheap). You'll get them both for the price of either a VFR or a GS alone.[/QUOTE
No problem getting your knee down on a GS, its an all day affair.
You just need road tyres.