What I measure on one bike doesn't necessarily transfer to another bike. Just 'cause the A-bike measures XX cm from bottom bracket center to (pick your landmark) doesn't result in the B-bike feeling dialed in. Yes, a good start, but I usually find that I'll make more fine-tuning adjustments as I ride the first time. All my seatposts have a small square of blue tape where the post meets the seat-tube, much easier.