bookworm
I have to admit that comparison was long before I discovered LOP operation, and that throws a spanner into any comparison, because there are different ways to operate an engine, especially for advertising purposes
I know about the Mooney being very efficient; as others suggest it ought to be. I had by then decided to not go for a single door aircraft.
CruisingSpeed
What do you mean by "EFIS"? Do you mean it had an EHSI (a Sandel or Honeywell colour LCD HSI replacement) or just a plain HSI?
The ADC (Shadin air data computer) is an option at around £5000; it tells you the TAS, the wind, and some sort of corrected OAT. The engine display was probably an EDM700 (£3000 or so) which is pretty well essential for engine management if one wants to avoid wasting a load of fuel.
Sounds like the anti-ice was the full TKS. That's about £25000 extra
THAT will mess up the W&B, but the other stuff won't.