Most wrpgs don't really feature open fields. That's mostly a Bethesda thing. If anything big open fields is more of a jrpg thing. As for lack of transitions, yeah, many wrpgs feature that. And for the better.
And getting surprised attacked by a crazy amount of enemies is awesome because you have to think and come up with a strategy on the fly. Something, that is lacking in 3d FF. FF12 was the first 3d FF to get it right. That element of surprise, that "holy shit I'm fighting like 10 dudes right now!!!" which every past 3d FF ignored, pitting you against merely 2-3 enemies at once at all times.
FF12 did a lot right, and the encounter system is among the best.
Oh man. That description of the bomb fight in the jungle was so
worthy. Actually having to use buffs and create dedicated healers
in a Final Fantasy?!!?!?!? 
BUT I DO USE BUFF AND HAVE DEDICATED HEALERS IN FF13 AND THERE IS NO BUFF WHICH TRIPLICATE THE HP OF MY PARTY THEREFORE MAKING IT ALMOST INVINCIBLE SFHJLKASFHLKJASFHL
*sigh*
anyway,i finished it,it was really good especialy coming from the emptiness that is the wii software library,i think the best part was palumpolum,it's probably the best looking place of the whole game and it's also where most of the story happens... anyway if i had to nitpick
1) while i don't think it's as bad as people says i do think the game somewhat drags,special offender are chapter 1 and chapter 5 which really are just a bunch of hallways and chapter 10 where i swear i got across the same gigantic room thrice,they could have made some cut since it's not like the game is short or that they didn't draw enough stuff so i'm not sure why they feeled into making these longer
2) the combat really shines with a party of 3 so having a party of 2 for quite a big chunk of the game was an awfull idea,this is especialy true everytime you have to play the sazh/vanille team since they both kinda sucks at offense,in fact i'm pretty sure the only reason sazh has the commando role is because otherwise team sazh/vanille would be completly unplayable,i would have add some guest character,you have them in chapter 1 when playing as snow so why not in the other chapter too?
3) serah is the only character i hate with passion,she's like the teenager version of holy mary and the whole love story seems written by an angsty teenager,everytime i had to see a flashback involving serah i wanted to choke myself! seriously WTF nomura? it's not like the other character sucks so why did you screw up this one?
4) while i do like the character they do tend to randomly break up in monologue about HOPE,DREAMS,FRIENDSHIP,FUTURE,DESTINY... sometimes it feels a little overdone especialy in the ending
5) the whole gran pulse bit seems a little tackled on,the heroes go there,read some magic stone and then return to eden none the wiser,the hell?
6) you have 6 character but there is little reason to use any team other than lighting/hope/fang at first you have a reason to pick between hope and sazh or fang and vanille since they offer different buff and debuff skill but then that difference is gone and you are simply left to pick the guy with better stat and skill combination..... on this note i'm gratefull that you don't have to use snow to get trough the game,seriously having to use a tank sucks,make the enemies hits everyone and have them hit moderately hard
7) the bestiary kinda sucks,while i don't like FFXII i did like how it gave you a story or stuff like that everytime you filled a page (tough the fact that you had to murder several monster of the same kind to completly fill the page was distinguished mentally-challenged but well it's FFXII.....) here you simply get shit like "USES THUNDER ATTACK!" and you can't even rotate the 3D model or something.....
mmm what else can i say that i haven't already said... the battle system is really good,you pick action but it happens so fast,especialy after your character learn haste,it's true that you are mashing X and pressing L1 once in a while but this happens in split seconds! it certainly beat a lot of other battle system,the final boss was quite impegnative,i filled all of my crystarium and he still gave me some problem (tough i didn't fully upgrade my weapon so maybe that explains why) also it's music rock!
the reason why i liked this game is the same reason i liked persona 2,i liked the character,i wanted to see how the rest of the plot hold up and what happened next,what place they went after,i liked the music,i didn't mind that every battle was solved by a simple cast of triple tech nor did i mind that the game was just one linear dungeon after another (no actualy sometimes you get a maze which is twice as annoying since you get jumped by random encounter everytime you want to backtrack)
bet that when the game hits the PSP in 2011 you aren't going to see any review talking about how horribly linear the game is but they will talk about the MATOOR character and the AWESOME strategy (which will involve casting a buff once in a while,healing when needed and spamming your best spell which the boss is weak too) like with nintendo if you are called atlus you can get by with any shit you want but be final fantasy (or viceversa be obscure and scrubby enough like my dear shiren :'() and prepare to carry every JRPG sin evah!
ultimately i would put the game somewhere near the bottom of the good final fantasy (which is still above FF8 and FF12 which are in the bad final fantasy drawer

) TWEWY still remains the best squaresoft game i played in recent years
oh also i got 585 gamer point out of it.... still trying to go for the 1000