On a big bed (5’6 and wider) a zip & link mattress can make great sense, as they are easier to handle and turn, and most easily allows each partner to have the level of support that suits them.  Also, if one partner gets up early, comes in late or simply tosses or turns a lot the other party will be less disturbed.

Savoir provides a padded ‘snake’ which fits over the zip to minimize any change in feel over the centre of the bed. However, if you actually sleep across the middle of the bed it is worth thoroughly testing how you feel over the zip. Most people find the "snake" works very well, but it is a personal choice.