Beguiler the magical animal thing right? Can you get it as a familiar ?
At the same level as the Pseudodragon no less.
Pikachu! I choose you!Isn't the Beguiler even more awesome, with it's Constant True Seeing?
Well, it depends on the situation. To use an ill-fitting metaphor, the Beguiler would be night-vision goggles compared to the Pseudodragon's radar.
For example, when encountering a pit trap covered by an illusory floor, the Beguiler would spot it, whereas the Pseudodragon would be useless. An invisible opponent? Either would pinpoint it easily enough, though the Beguiler wouldn't have to deal with concealment if delivering a touch spell to the enemy. An enemy using mundane stealth? Located automatically by the Pseudodragon, but it could sneak past the Beguiler's vision. Someone around a corner or through a wall? Mindsight reaches through solid objects, unlike Blindsense or True Seeing. A mindless automaton just around a corner, programmed to attack the first thing that comes within range? Would catch either of them by surprise.
So it really depends on what you want to do with it. Beguilers also have some other advantages, such as speech (magic item activation!), +8 hide (while dry only), the ability to wield a manufactured weapon in addition to their natural weapons, and the multiattack feat as a racial bonus.
It's a shame their LA +0 is cohort only. They'd be a great PC race.