Got my Monk to level 50 last week and have been enjoying dabbling with other classes and doing some trade skills. I took my time leveling and I read every quest including the side quests to collect 5 bear asses but it was still a lot of fun. I didn't keep up on my Grand Company ranking like I probably should have so now that I'm 50 I'm still working on moving into the last rank of enlisted (Sergeant 1st Class to Chief Sergeant I think). Once that's done I've got to rank into the first Officer so I can unlock Hunts.
There's a ton of stuff to do once you hit 50 as well. Quests have popped up everywhere so there's no shortage of things to do or work on. I've been using this reddit post to guide me and it's a pretty good overview of progression it seems:
So You Just Hit Level 50 in Patch 2.3. I've been working on my relic weapon quest line and it's a lot of fun -- big quest too and I hear you can upgrade the relic weapon later to higher tiers. I think I've still got to do Amdapor Keep and then three Primal hard modes.
I can understand how people might not like the combat because it feels slower paced because of the GCD but I actually like it. It's got a deliberate, methodical flow to combat which actually reminds me somewhat of combat in LOTRO which I also liked, but I know a lot of people hated. It's definitely much slower paced than most games, especially at the lower levels, but I noticed that the higher you get (at least with my Monk) you start getting a good amount of abilities to use and cooldowns to pop in certain situations, so it's not like you're only hitting 3 different buttons later on like it sometimes is at the lower levels.
The graphics, sound and music are top-notch as has been said a million times already. I wish that there was more VOs for the quest dialog but it's not a big deal.
I also really like that you can use a gamepad to play this. Sometimes when I'm just doing solo questing I'll switch it to gamepad and it feels really relaxing. Also, since it supports a gamepad, this is the first MMO I've ever been able to get my wife to try and she is enjoying it as well but it's slow going for her as she has never played an MMO before -- there's lots for her to learn.
When I first started I was concerned that the game may have been dying as it seems like subscription MMOs aren't doing that well anymore, but my fears were put to rest. I'm playing on the Exodus server (US) and there are people everywhere. The lower level zones are not packed all the time, but there's always a decent number of lowbies and vets leveling new jobs running around doing quests and fates. The towns are always packed full of people (more Limsa Lominsa and Gridania than Ul'dah) and places like Mor Dhona are crawling with high level people everywhere.
Overall, I'm really enjoying this game and I'm glad I gave the free trial a shot. I've still got a TON of stuff to do and if I get bored playing my Monk it's as easy as using the gear set list to switch to a completely new class.