Unless you're planning on becoming a B/P(Barrage/Pet) ranger and need a Dire or Elder pet you don't really need to change your pet. People generally only do so for vanity purposes.
You would think that the later on in the game the stronger/better the pet are, and if you charm a Melandru's Stalker (the first pet in charmed in Ascalon/noob land) that it would be pathetic... but I personally don't think that pets are very powerful no matter what animal they are... I just love taking my Tiger out .. for company i think?
Unless you're planning on becoming a B/P(Barrage/Pet) ranger and need a Dire or Elder pet you don't really need to change your pet. People generally only do so for vanity purposes.
Nonsense. Dire Pets do a lot more damage then Heary ones and of all the pet builds, B/P is not particularly in need of a dire pet. If you are serious about Beastmastery, a Dire evolution is probably the one to go for.
But you'll likely need a slightly stronger character character with a few high damage petskills to train a pet to Dire (or heroes to death-level it), dire evolution requires that the pet does all the damage and you do very little.
There are various guides around here to help you train your pet to dire