mate, i was in halfords the other day to buy one of these, decided to get either the origin b2, RA2, or RA compact. decided to go for the compact as it was such good value for money..
never felt a RA2 but the compact does feel quite cheap, but its small and neat, and tells you the speed limits. i think the only difference is you need to buy the laser detector separate for the compact? i might be wrong though?
i didnt go for it as the guy in the shop said its not worth the extra £50. he said it will only pick up the mobile vans when they target you, and by that time you only have 0.8 seconds to react.. could be rubbish info but this is what the salesman told me! lol
still havent properly updated it yet and it has picked up all cameras so far, and even warned me about where mobile vans sometimes sit, blackspots, school zones, and average speed zones.. brilliant value for money, specially when i can only get 6 points on my liscense
hope this helps
justin