I played a few hours of Guile last night. People can feel free to correct me here as these are just my personal impressions:
*Guile combos are pretty hard for me. I haven't struggled in any of the combo challenges yet but his took a while due to the charge combos. I wish his charge time was lowered for a scrub like me, seems out of place in a game like SFV.
*L Sonic Boom doesn't have the same anti air utility anymore. Like if someone is jumping right in front of you the Boom is now more likely to go just under them rather than catch them jumping in. There's a reason for this.
*Can't do America's favorite combo anymore except maybe in corner but it's better to do some other combo in that situation (talking about back HP x 2). Major bummer for me.
*Another bummer is you can't do upside kick into cr.MP. Not only that but upside down kick can't be used by holding back, can only be used by doing forward HK which again makes combos after harder. And the only combo I could find was counter cr.LP into special after it. Not as good as in SF4.
*cr HP doesn't pop them up as much so they are still very close to you afterwards. Not a big issue. Also it starts up slower from the looks of it which makes it easier to get snuffed.
*Flask Kicks don't appear to be invincible.
*Overhead is a lot slower. Online everyone easily blocked it.
*St LK MK target combo is pretty nice though.
*Guile's normals are still pretty good despite most other characters having stubbier than normal limbs.
*Air throw is still pretty good for the most part.
*That slow crouch walk is done by just holding down forward. It's alright, not crazy or anything.
*Now we get to the good stuff... the V Skill is AMAZING! It feels like such a natural fit for Guile that I am now surprised that we used to play Guile without this tool. It gives Guile something to do instead of just holding down back. You can do this move out of crouch block while retaining your Flash Kick and Sonic Boom charges. You can throw it out like a Light Sonic Boom in the older games if you expect them to jump and they might either jump in it (and you get a small juggle). It also absorbs fireballs so with this it's near impossible for other fireball characters to gain advantage over Guile as it should be as Guile is supposed to be a specialist. The Booms that come out of it are double hit durability so it's like throwing EX fireballs all the time. The whole V Skill sets up a whole new layer of mind games in the neutral as you keep the opponent guessing on what you want to do. The V skill also allows you to build V skill pretty quickly despite Guile having a 3 bar Trigger.
*V trigger is cool but I have not tapped into it's potential yet. Yea yeah it allows Guile to do a bunch of insane fancy combos but it's application in neutral is very strong because you can really pile up the chip damage with it.
*Sonic Hurricane seems better than before. You can actually combo this off of a Flack Kick if you cancel super fast (not that easy to do) . Only issue is that it competes with the EX meter for Guile and you kinda need the bar for EX Flash Kicks and EX Booms.
*Back fist and Straight crush counters are pretty good. You get a solid combo off of back fist and Straight crush counters creates a lot of space for you. At close range you want to frame trap with st. HP CCwhich goes into d/f HK into EX Flash Kick.
*Basic combos for Guile are really limited compared to other characters.
I think the new V Skill/Trigger stuff save Guile because without those I would've been super disappointed with Guile. I wish he had easier basic combos to do white retaining his fancy V trigger shenanigans. The V skill is excellent though and is a definite scrub killer.