Skiesfull,
Well, it depends.
Altho all L10's were fitted with DLC, only the -500 models were fitted with MDLC.
These are completely different animals.
While DLC was activated when the flap HANDLE was selected beyond 30 degrees, and was designed for accurate pitch control during the approach phase, MDLC, using some of the same spoiler panels, was used in cruise only, for the overspeed condition.
Also, as I have flown several ex-BA -500's, the ACS continued to be active, for if it was not, inflight weight penalties were imposed.
Likewise for MDLC, inflight weight penalties if not serviceable.
Now, as to the 'underpowered' issue.
While it is true that the -1, -50, and -100 models fitted with the -22B engine could have used more power, the -200's, and -250's fitted with the -524B02 and -524B402 engines were VERY good performers, and I have a lot of hours in these machines.
TriStar...one fine aeroplane.
An oldie but a goodie.
