the rieger grill will fit perfectly - if the person fitting it does it properly. if you sit it in place and spend 2 minutes with the sikaflex then yes its a bad fit. if you spend an hour or 2 trimming and shaping and getting the fit you want then its a perfect fit.
first 2 pics of rieger grills i came to on my pc. the bottom 1 was fitted in a bodyshop - fits perfect
top 1 is my car and was fitted by me in half an hour - fits perfect
yes its more expensive, but then its different to all the other gsi grilles out there. also by the time you've had a bonnet extension fitted, smoothed, and resprayed the bonnet your talking Ã‚Â£150 so the grill is a saving.
if your getting a bonnet extension, please dont waste money on a fibreglass stick on 1 - it'll crack and warp within 6 months. pay the extra and get the bonnet extended with metal. a decent bodyshop will charge you an extra Ã‚Â£30 or Ã‚Â£40 to make a metal 1 - about the same cost as the fibreglass 1.