I know there are probably other places to post. However I have a mostly overrall opinion on a few things and didnt' want to break it up.
I started playing a while ago, before even river city was around, I have been in and out to check out the various changes that have been going on. Here are my thoughts.
Gameplay -
I like that there is a new format (capture and hold points). Although I wish that it was more likely it mattered, or that you could respawn in order to try to keep taking those points until one team made up the 750 points needed to win. Unfortunately as with capture the enemy base the game is more about just killing the opposing team. This would also cause the light mechs to have a great advantage in stopping captures, and to do some sneaky caps. I understand that C-bills and xp would go through the roof if they stayed the same and would have to be tweaked. But I believe the change in gameplay would be much more exciting and touch on a different skill for some pilots (rather than just aim).
I have enjoyed the changes to Guass and PPC's and even LRMs. These were all a bit different before and I like them a bit better. Now for the specific comments.
SRM's (mainly 6's), these hit very hard and with more mechs around (we will get to those later), boats of SRM6 can shred an Atlas in just a couple rounds. I would be more ok with this if the SRM's had a small splash radius, so when they ram you to make sure the spread is contained they also take some amount of that damage (most noteably they would take it in the location that had the SRM's in the first place, making it that much more dangerous of a strategy.). I do however like the fact that it is valuable to have SRM's so I am not asking for them to be nerfed out of builds. I just would like them to be used in a more honest or intuitive way (Missiles explode. don't get close.).
Ultra AC 5 - I really want to like this weapon, however I can never seem to get it to fire more than 3 rounds before it Jams. I have decided to replace mine with AC5's because over a fight I will actually get more rounds off without the ultra. I just think a small tweak in the jamming chance would help this a bit.
ECM's - I actually like these.. I know they are annoying to lots of people, but I do like the change in the game that they provide. They also seem like the reason LRM mechs have slightly more trouble nowadays. Maybe they are to much like some people say, but I haven't played with/against these enough to know.
Stalker - This is probably my biggest issue right now. I was so excited when I heard this mech was coming out, it used to be one of my absolute favorites. I even used the callsign back in the battle pod days. What I don't like about this thing is a) the look. It looks like a Cat thats missing it's ears most the time, which makes it a harder target than a mech 20 tons lighter.

Overrall very happy where things have gone, and I understand it's still in beta. I am still hoping for other modes (as stated above)..
TLDR - Game is good, but a stalker killed me with SRMS so now I am QQ'ing.

Actual TLDR - Game is good, here are my opinions on what could be tweaked to make it things slightly better.