Against Runflats
1. Tyre pressure checking on average twice a month & judging on how accurate on inaccurate they may be the garage one can be this is annoying but a must
You should check them more often that that anyway.
2. The thought that if i do use the runflat for the purpose its intended & then the thought of having to fork out for a new run flat after this, surely this is not on as that the purpose they were designed for!!! & there not cheap.
I didn't have time to wait for a internet price and had to replace a runflat at a local tyre shop. £160 per corner, nice! You can't even repair them either 
3. The many comments about runflats & there dislike to pot holes but this will also be the case of non runflats though. Also the price of repair that my friends has just had to folk out for her mini after a pott hole disaster.
Pot holes will still do the same damage regardless of tyres. Ride quality is equivalent to concrete too..
4.& many more but that just a few
Against normal tyres
1. The non ability of driving on flat & the damge that can be done as i drove flat before!!
You still can! One can of holts tyre weld and a compressor in the boot...
2. The thought of being stuck in the country lanes on the way to work with a flat & waiting for recovery -(
... for situations like above when you can't wait for recovery.
3. The thought of having no spare & no space to store a spare
Again, tyre weld for emergency situations.
4. Will the run flat system accept non runflat tyres.
There is no "run flat system" as such, yes the runflats fit the rims and yes they work with the pressure sensor, but then so do normal tyres.
5. Will the handeling/cornering be as got with normal compared to runflats
I changed to Goodyear Eagle GSD3 215/40/R17 and I wouldn't believe someone who said this but seriously, the handling in damp conditions is probably as good as the dry handling was with Pirelli Euforia Runflats!!! Handling is massively improved.
I also saved 5KG's of unsprung weight switching to the 215/40 profile. Turn in is still just as sharp but the grip is monumental, my MCS has 30/40hp up on standard and has less understeer than it did with runflats and less power!!!
6. You can repair some puntures on normal tyres rather having to bin the whole tyre.
7. Much cheaper I can get 4 top end Goodyears for less than two Dunlop/Pirelli runflats.
8. Ride quality is much improved, doesn't crash into bumps. Less bang and more thud if you get me?
9. Better braking, improved grip and a little more flex in the tyres help braking.... a lot.