I have ARK springs fitted to my 370, they give a drop of 30mm front & 25mm drop at rear.
Supplied & fitted at cougar store couple of months ago, just enough drop so the gap between the arch and the wheels is closed but still ok on our roads as it's my daily driver, ride comfort is not really that much different to oem and I can just about clear speed bumps as long as I go over them slowly, really pleased with the results
Possibly could have gone a bit lower but as it's my daily driver I think it's just right