Group 1: Level 5
Group 2: Level 5
-How long do you play for?
Group 1: 8ish hours per session every 1 or 2 weeks.
Group 2: 7ish hours per session every month
-How many combats do you play?
This varies in every session!
In both groups, we have had entire sessions without a single combat (but made entirely of roleplay encounters) but in our most combat-intensive sessions so far, in group 1 I think it was 4 combats, in group 2 it was 5 combats. But we don't like it any less with fewer combats, it's just a mixed bag every session.
Group 1: Each combat takes about an hour and half. Though some have been longer (I think the longest has been two hours or so) and some have been shorter, say an hour.
Group 2: Each combat takes about an hour. Though some have been longer (I think the longest was an hour and half) and some have been shorter (I think the shortest was 30min, though it wasn't meant to be a challenging encounter, merely a delaying force sent by the real threat that they met later on).
Disclaimer: rarely do we actually watch the clock, the above time frames are just from times that I happened to notice the time. But, usually, I am not watching the clock unless it's on accident.
-How many players do you play with?
Group 1: 6 players + 1 DM
Group 2: 5 players + 1 DM
-How long do you roelplay for outside of combat?
As said in an earlier answer, our sessions vary in that roleplay-combat spectrum each game. We have had entire sessions made up on one extreme or the other, and other sessions fall somewhere in between.
-Does it sometimes feel like playing a boardgame?
For me, personally, no. But I will qualify that and say our groups are made up of people who (generally) get very in to the plot and character motivations and such. So combats (and noncombat situations) really are just obstacles along the path of achieving the in-character goals.
Having said that, I played with another group for a one-shot game. _that_ felt like a boardgame to me. No one was really invested in their characters or the plot and it was just "I have a set of stats" and "the monsters have a set of stats" set up the board and let's go at it. While there is nothing wrong with that, it just isn't the style I tend to prefer, but once in a while that is okay with me too.
-Do you change any of the rules?
Neither of our groups change the rules all that much.
Though we more or less don't do skill challenges by the book, nor do we do treasure parcels as presented... but , beyond that, the "rules" remain largely in tact with only a couple minor tweaks for flavor of the campaign (i.e. a race that might not be allowed because it doesn't exist in the world, and so on).
We've been playing around 9 months. We're 8th level. Combat is fun but with 5 players, even using power cards, seems to take around an hour per combat. It seems when we play 1 combat, it's way too easy. We have so many healing surges and all our dailies. But when we play 3 combats, 4e seems to really shine with action points, milestones, dailies and by the 3rd encounter things feel really dramatic like they can go either way. But with a 4 hour session, that leaves very little room for roleplaying.
Just curious -- have to considered not forcing the end of the adventure to coincide with the end of the session? By that I mean, the PCs can advance maybe as far as they can get at a leisurely pace while stopping encounters long enough to do some more noncombat encounters that you want to include.
And then stop when you are out of time (though watch the clock before any fight to see if you could reasonably finish it before it's time to go, and then stop there).
Everyone would take notes as to which daily powers are used up, how many surges they have left, how many hit points they have left, how many action points they have left, which magic item daily power uses they have, etc.
Then, pick up the next session where you left off.
This would allow you to get in some more RP time that you seem to want more of.
Of course, the logistics may make it difficult - I don't know if you have rotating players or what not. And if people miss from one session to the next it would make this type of a setup more difficult.