Here are three pairs for one family I'm looking into, Kellogg in Essex. The Feet of Fines have been published and are online (link below).
The match between the two is pretty exact. (I have written out the abbreviations.) In Common Pleas they were only interested in the money paid to the crown, while the feet of fines contains the purchase price.
1560 Easter/fronts b 1044
Essex. Christopher Sumner pays ten shillings to have concord with Thomas Kelloge and Marion his wife concerning one messuage, one curtilage, 20 acres of land, 10 acres of meadow, and 16 acres of pasture in Ultyng, Hatfeld Peverell and Boroham.
Easter & Michaelmas 2 & 3 Elizabeth (1560)
Christopher Sumner, plaintiff, Thomas Kelloge & wife Marion, deforciants. 1 messuage, 1 curtilage, 20 acres arable, 10 acres meadow & 16 acres pasture in Ulting, Hatfeld Peverell & Boreham. £80.
1561 Michaelmas/fronts a 489
Essex. John Pyke pays 6 shillings 8 pence to have concord with Thomas Kellogge alias Kellocke and Marion his wife concerning 2 messuages, 2 barns, 2 stables, 2 gardens and 2 orchards in Malden.
Michaelmas 3 & 4 Elizabeth (1561)
John Pyke, plaintiff. Thomas Kellogge alias Kellocke & wife Marion, deforciants. 2 messuage, 2 barns, 2 stables, 2 gardens & 2 orchards in Malden. £40.
1564 Hilary 1215/dorses 652
Essex. Thomas Unwyn alias Ounyon gives the Queen six shillings eight pence for license to concord with Edward Ryche alias Kylhogg; Cecily his wife; John Cornell; Judith his wife; concerning one messuage, one toft, one garden, ten acres land, two acres meadow with appurtenances in Sampford Magna and Byrdebroke.
Hilary 6 Elizabeth
Thomas Unwyn alias Onnyon & Thomas French, plaintiffs. Edward Ryche alias Kylhogg & wife Cecily & John Cornell & wife Judith, deforciants. 1 messuage, 1 toft, 1 garden., 10 acre arable & 2 acres meadow in Great Sampford & Byrdebroke, Def. quitclaimed to pl. & the heirs of Thomas Unwyn. £40.
Feet of Fines for Essex, Volume V
These are the two I posted earlier. The description of the property is the same but there are two extra names among the querents. Possibly trustees or agents?
In Common Pleas (CP40):
1491 Hilary/fronts 44, fourth to last entry:
Herts. Bernard Brocas gives the king 6 shillings 8 pence to concord with Robert Mede and Joan his wife on a plea of covenant for 40 acres of land, two acres meadow in Long Merston, Coblecote and Wyvelesthorn in Tringe.
In Feet of Fines (CP25):
This is the final concord made in the King’s court at Westminster, Octave of Purification of St Mary, in the sixth year of Henry VII before (list of judges) between Bernard Brocas, esquire, Richard Lee, John Burdon, querents, and Robert Mede and Joan his wife, deforciants, for 40 acres of land and 2 acres of meadow with appurtenances in Long Merston, Goblecote & Wyvelesthorn in parish of Trenge, etc.
So there isn't a lot of extra information in one or the other, based on this small sample. The main difference is that we have indexed about one in ten of the CP terms between about 1345 and 1565 (about one in six from 1509-1550), and there many Feet of Fines after 1509 that are not available online, either in the original or in print.