I've has an 03 Cupra and now have a 54 plate Cupra R. I had the Cupra re-mapped and it had more torque than the R but the power tailed off quicker, this was the K03s running out of puff... I however had no problems with the brakes so perhaps the braking was an issue on earlier LC's? The Brembo's on the R do have a totally different feel though which you need to get used to.
The LC had a slightly more relaxed ride, so on Motorway journeys it was more comfortable than the R and quieter. The R is more planted in corners and has slightly less lean that the Cupra which gives you more confidence. However the LC does handle pretty well (I had S3 strut braces fitted which made it better).
Another thing to mention is the fuel consumption. I get on average 300, maybe less to a tank. Even on a run at 80mph it's not much more. The LC would easily break 400 miles a tank on a run, think the most I got was 430ish which is impressive from a 215bhp (re-mapped) motor.
In my opinion a standard R is perfect, the power delivery from the standard map is smooth and the car really shifts. The LC is slightly underpowered and the re-map does the car justice. If you want to watch the pennies get an LC, re-map and you'll save on tyres, brake pads, insurance and fuel. If money is no object get an R....!
Something to add - On a back to back test drive, you won't notice much difference between the two on the handling side of things. This is what I thought anyway when I test drove originally and got the LC. You need to have both cars for a long period of time to appreciate the difference between the two, and there is a difference.