T esters are a time release delivery system. Some products have ester groups that are removed more slowly [heavier] than others [ligher], creating a flatter longer release curve. If you inject more often, there really is no need for the longer lasting esters or proprietary blends, then ones choice is more determined by cost and availability. T cyp is typically a cotton seed base and T eth sesame seed. Rarely, one might be allergic to plant protein traces in the base oil and then one has to use the other.
Longer lasting esters or blends that are injected every week or two will always cause peak/trough problems for many. The only thing that addresses the problems of unsteady levels is frequent injections; which also reduces E2 levels.
Heavier esters will yield less T than lighter esters.
For those who need anastrozole to achieve optimal E2 levels, the need to match anastrozole dose to current T levels really dictates a need for steady T levels. This requires frequent injections and longer acting esters are then not compelling.
All T esters yield bio-identical T after the ester groups are removed. So in that regard, they are all interchangeable. If one will not inject more often than once a week, heavier T esters might easily feel better.
hCG and anastrozole should be dosed EOD, injecting T at the same time makes for a good routine for many. Then the longer acting esters have no added value and deliver less T.