Mate, go and drive one and see what you think. I personally wouldnt have an older model, but the newer ones I decent looking. Yes a remapped LCR may keep up, in a straight line, but through the twisties the Impreza would walk it, unless it was someone who couldnt drive sat at the wheel. Then you can talk about modding too, as a modded scooby would easily beat a modded LCR, imo.
The worst thing will be running costs though. As above, 4 new tyres at a time, plus the fact that it needs an oil change every 3000miles to keep it in top shape. Also you can add in the 20 mpg, or less, figure in to it.