You will probably get more sides from sust...the 4 different test esters will not provide stable blood levels of test, unless you dose it at least E3D. Test Enanthate will provide more constant blood levels when the desired concentration is reached.
As for gains, you will get faster gains from sust, because it has propionate/phenylpropionate it in it, which have short half lives. But fast gains do not mean better gains, they usually just mean bloat. I would prefer test enanthate myself, but sustanon is still a great drug IMO, when dosed at least E3D.