No hair being split by me, simply a pragmatic decision. We live on the outskirts of Rochdale and, since our train service (Oldham loop) was withdrawn in Oct to allow Metrolink to bugger it up, we have to take a taxi to R'dale station, change at Salford Crescent then walk quite a distance (if T3). From home to gate is about 1.5 hours on a good day. On a Sunday you can double that as it means Metro across town to catch train at Victoria.
From LPL, throw bags in car, 40 min drive to pre-booked parking, 5 min walk (if that) to check in. Same on the way back. No contest.
Err... why not throw bags in car, 30 min drive to pre-booked parking at MAN, 5 min walk (if that) to check in. If you've got a car, why bother with taxi/train?