I prefer Constructor. I personally would probably not use Erudite for it do to it's limited Unique Powers per day and that you lose the ability to learn powers apart from the level progression once you go past Erudite lvs in Constructor, and that the ACF for Shapers at 5th level from Mind Eye is pretty damn nice, but this is probably only because I like to use PP regeneration loops and buffing hard with all the powers my Character knows.
Erudite would probably still be a bit more powerful though if you are not buffing yourself with multiple powers and more or less acting as a toolbox.
Malcovoker is a lot more versatile and powerful then Constructor overall though, a given with spell access which is superior pool then psionic powers, and that summon monster at higher levels has quite a bit to offer.
Constructor is a bit more fun IMO though, sense you have an easier time customizing your summons.
I personally quite enjoyed my Constructor I played a few months back. She had a plant them going on and summoned plant monsters to fight for her. The Aesthetics were pretty fun, with her wrapped up in a flying constructs vines hovering over battlefields commanding legions of constructs.
That game had a lot of big scale naval battles too, and with a PP Loop and constructs that lasted minutes per level, she was quite effectively a one man army destroying ships left and right.
Heh, now I am reminded of our parties 'Wonder Balls' (Balls with a one time effect of a Rod of Wonder, which were shot out of cannons).
Now that I also think about it, I also have a Malcovoker/Fiendbinder/Cosmic Descryer in the same world as well. Quite a fun fellow, though I have barely had a chance to use him as of yet (and really don't summon all that much with him either sense he is a total tweak).
Overchannel and probably Talented are musts to make your Constructs as big as possible, If you go that route. If you can use 3rd Party Hypercouncious, Dreamkeeper is also pretty solid addition to take before and after Constructor, giving your constructs Fast Healing, Concealment, and a few other benefits from the first few levels. Some of the 3.0 Mind Eye Articles have some feats that buff your Astral Constructs as well, so you might want to look into those.
This is of course assuming you go Constructor.
Damn, I wrote a Wall of Text.