Congrats on your new find. Getting a Moulton TSR with only a couple rides is something I'll wager a lot of us would like to have.
I've ridden the TSR, and I can't say that I ever thought it was a high-performance bike. Does it lose efficiency because of the suspension? Hard to say...maybe a little, but one doesn't buy it for speed, one buys it for elegant engineering and that hard-to-describe ride quality, which can be addictive.
Wanna go faster? First thing I'd replace is the Wheelsport Sunny wheelset. For not much more money, the Wheelsport Smart 1.0 sports a higher-profile rim which in theory is more aerodynamic. Of course, you could go with any 406 wheelset you want, and there are others...just mentioned the Smart for starters.