Repliglass have a good reputation. I have not used their front guards.
I have Alfa Fibreglass front guards (purchased back in like 2009 mind you!) and I'm fitting them up currently. They certainly have needed some work, but I haven't seen any fibreglass panels that don't need work. I would describe them as quite usable, but you'd want to have your eyes wide open going into it. Don't expect any glass panels to fit without finessing.
The bottom bit where the two bolts normally go into the sill... that was out of position for example and I personally just attached mine there in a different way, which wasn't extraordinarily difficult. This photo may be adequate to demonstrate:
Overall, mine follow the profile of the nosecone reasonably well, follow the line of the bonnet very well, are a little short (creating a wide gap) where they meet the door (it's quite easy to extend the panel a few mm here with a fibreglass resin/powder combo and then sand back to your preferred gap width).
The frame on mine was maybe not glued in the perfect spot - so it forced the guard to hang out a little far from the car body, rather than tuck in tight around the bottom of the A pillar etc. I sectioned a small piece, like so:
That wasn't a whole lot of work, and it did remedy the problem.
Edited by Heath, 03 February 2020 - 11:55 PM.