Er... Manual Thrust?
Did about 10 years on CFMs, then 4 years mixed, before retiring 7 years ago. Agree with all I've read here. Have never liked EPR as a means of power indication – except perhaps for take-off – for the reasons others have highlighted. In the 'Seventies, we had similar problems on the BAC OneEleven when converting from early Speys, which used N2 as the main thrust indicator (except for take-off, when P7 was also checked), to the later Speys.
Fuel flow indication should be a useful tool but, if memory serves, is almost useless when the throttle is moving, when you may need it most.
Presumably, the N1 is as good an indication of changing thrust on the IAE as on the CFM (at a given density altitude), so CFM-sized N1 "gauges" would be the answer. The two snags that spring to mind are:
1) lack of space on the display;
2) the misguided (in my opinion) policy of most airlines to discourage or even ban the use of manual thrust, despite the A320 having the best "manual" throttle of the seven jet types I flew. Most of the once-a-month brigade would never dream of it. And the A/THR never fails, does it?
The other thing I liked better about the CFM was the comparative ease of inspection on a walk-round, particularly if you were wondering about a bird encounter on the previous sector.