I've been a longtime member at HPUMC and really enjoy it.
Took a short hiatus and moved over to Munger Place after I got divorced (was married at HPUMC and ex's family attends church there). Andrew Forrest is the preacher at Munger and I really like him. I attended church there for a year or so with no complaints, but then one Sunday felt a draw to go back to HP to try it out. Something about it just felt like home as cliche as that sounds, so I have been going back there ever since.
Would be happy to answer any questions you might have.
HP is definitely more of a big church feel in my opinion. As someone who was used to having someone to go to church with and then was suddenly on my own, it was hard for me to go and not know anyone. Probably a little bit of my fault on that as I'm not the most social guy. I think you'd probably have to work a little more to get involved there.
Munger feels a little more like a close knit family. Lots of younger East Dallas folks. But they don't have a formal choir (which I enjoy), and I would guess they don't have the amount of programs and groups that HP does as they are a smaller church.
Just for reference, I'm 35.
Like I said happy to answer any questions for you.