Um Rotbarts Aussage zu untermauern:
"Augmentation S. 128" schrieb:
When a character has an implant removed to be replaced or upgraded, this leaves what is known as an “Essence hole”—a disparity between the total Essence Cost of her implants (see Cyberware and Bioware, p. 84, SR4) and her current Essence. This Essence hole never “heals” naturally. It may, however, be used as a “credit” for any new implants of the same type (cyber- or bioware)—simply deduct the Essence hole from the new implant’s Essence cost before applying it to your total. In other words, if you remove one cyberware item that had an Essence Cost of 1, you may install up to Essence Cost 1 of new cyberware without lowering your Essence total. Any cost over 1 would be deducted as normal. Note that a bioware implant would not be able to fill that same hole, however—cyberware only.
@Rotbart: Hast Du etwas gehört, dass ein Erratum das korrigieren soll?
@Essenzrechnung: Wahrscheinlich gilt auch für virtuelle Ware die Halbierungsregel. Also bekommt der Charakter in meinem Beispiel laut RAW 2,6 Essenzverlust für 1,9 Bioware