I bought this day one after playing the beta. I probably put about 10 hours into the Beta and have logged 50 on this so far - that makes it my fourth most played game on Steam.
What you need to remember is that you effectively have two games with Evolve - one as the Monsters and one as the Hunters. Both games also change significantly depending on the character\monster you pick. Anyone that plays it for a few hours and says it's samey hasn't give the game a fair crack of the whip. There are also three other game modes to the main Hunt mode and although Hunt is my favourite - the others require a different approach to the game and that is refreshing.
I'm a billy no mates so I generally play as the monster so I can give you a better idea from that perspective. Each of the three existing monsters plays very differently. There is a suprising amount of depth to how you play as each one. How you level them up, when to sneak, when to run, leaving false trails, when to fight - I'm still learning new tricks and techniques. Admittedly, a lot of matches do follow a familar pattern, but that's not to say that there are not stand out moments. I play mainly as Wraith and when I recently got matched against a pubs team on my favourite map I knew I was likely to win, but they caught me at Stage 2 in a perfect Dome where I had nowehere to hide and they almost killed me. It ruined me for the rest of the match, but I got to stage 3 and the final battle was so close. I eventually got them down to only the medic and went in for the kill, but my health was so low from earlier the downed Hunters killed me with pistols a second before I landed the the final blow. Yeah, I lost but it was a fantastic intense match.
You have mate to play with so your enjoyment of playing as the Hunters will be much greater. Each class and character is so well designed that you will have a fair few favourites to choose from. Working as a team you stand a very good chance against the monster and it is so satisfying to finally kill them after a long battle.
In my opinion it is a fantastic game and its unlike most other games out there. The recent blanace patch has improved things further and the new monster Behemoth looks great - this was originally a pre-order bonus, but you can pick it up for 70p from key sites.
Watch a few youtube vids, but I think if you have a mate that will play it with you regularly you'll love it.