What is the general consensus on these two choices? Are either actually good at all?
Pseudodragon are generaly considered lackluster familiars, their redeeming point is their blindsense.The poison DC scaling on the master's level is DM fiat (whether or not it is an effect based on HD), so ask him first if you want to use it, otherwise you'll never make it work.
Faerie dragons have more uses, first they cast spells as a sorcerer, so no die roll needed for most wands. Also they have good SLA, but lack some nice detection ability.
Both have telepathy if you want to keep contact, but telepathic bond is better for that.
If you are into good familiars and if your options are not set on those 2, I suggest you take a look at the lyrakien and the silvanshee.
The cat is the second fastest familiar, a decent backup cleric and an universal translator (think C3PO in cat form).
The little tinkerbell is the best one around at UMD, a decent archer with a good bow, have some of the best detection abilities, a crazy mobility (fly speed and freedom), and you'll have your own personal pin-up :D.
Both have nice SLA and init to make things better.