Reallocated sectors are completely normal for HDDs and SSDs. No drive is 100% perfect otherwise yields would be too low and drives would cost 5-10 times as much. To counter these imperfections, HDDs and SSDs have reserve space to remap these bad sectors.
Ok fine, so when should it be replaced? if the Re-allocated count starts jumping on a regular basis?
I have another drive in this computer, a Seagate 2TB drive for as long as I have had the Intel SSD drive and that doesn't show any Re-allocated sector counts
You should be concern when:
A) there are suddenly more reallocated sectors
B) the drive cannot remap the sectors
Simply put: worry about it if the number starts increasing rapidly over the course of a month, if the SMART attribute adjusted value reaches the adjusted threshold, or if the number is extremely high (hundreds or thousands).
On SSDs, this number indicates the number of flash blocks which have gone bad/cannot be used for writes any longer. One LBA is approximately 4096 bytes, or 512 bytes.