I have it as well (BITEY GIVE ME YOUR PSN, I haven’t looked in the name threat yet so..) and yeah its pretty awesome, though definitely some gripes about a lot of the game. The tutorial “mode” seems to go on a bit too long and yes, it is quite linear at first. Once you are dropped off in
gran pulse
you get to run around all over the place and do missions, etc. To get there though takes about 20 hours or so, which is relatively annoying. The characters seem to be pretty weak/whiny but the story is pretty good with plenty of twists and turns, as per the FF name. The battle system is quite amazing, I love the ATB and I love paradigm shifts. I dislike not being able to control other characters and decide their abilities, but it actually works a lot better than I thought it would when I first started playing. Unfortunately the AI of characters are still pretty stupid. I run Syn/Comm/Sent to begin with and while my Sent will provoke, etc on a high level/powerful mob I’ll still get cleaved by a mob randomly after my Commando will attack 2-3 times from behind. Wish I could move around at least a little bit, give me a movement bar to regulates how much I can move in combat so I can position myself out of being hit by AoE abilities. The difficulty scale jumps at times, you’ll breeze through most of it and then encounter mobs or bosses such as Cid or the Primarch and be stumped for a bit. I blew the Primarch up but Cid took me ~10-15 tries because he would combo Lightning into the air and absolutely trash her.
I agree with the “if you liked FFX, you’ll probably like FFXIII” statement though, there is A LOT of similarities with the two games but at the same time very different. I like the characters and system in FFX a lot better so far 
. The eidolons were a lot better as well even if Yuna was the only one who could summon them and they didnt turn into some funky vehicles >>.