A tenanted delivery has to respect the Residential Tenancies Act, 2006, which governs how and when a lease can be ended for a sale and what notice a tenant is owed. Ending a lease incorrectly can delay possession or expose a seller to a claim.
An investor-buyer will usually pay for documented, in-place rent more readily than for a projection, because it removes their lease-up risk on day one. An owner-occupier, by contrast, will often discount an offer to cover the hassle and delay of waiting out an existing tenancy.
Knowing which buyer you are most likely to attract is what should decide the delivery, not a general rule. Get your hand-reviewed valuation from Joel Dyck.