M103- Worth upgrading to top gun?

The_Chieftain:   This is one of those cases of the whole being better than the sum of its parts. Yes, one would need 245,000XP to get the E5 instead of just 185,000, but once you've spent that first 60,000, the remaining 185,000 are so much more fun and go by so much more quickly because of the better gun that you're not actually losing out on as much time as you think you might before starting off. I highly, highly recommend going for E5 with the top gun, unless there is some time-critical reason "I must have a T110E5 for a contest or some such" for you to beeline to it.