It's an XM15-E2S with 20" barrel to be exact. I gave it a decent cleaning before taking it out for the first time and so far have put almost 200 rounds through it with no feed/extract problems. I did have some trouble getting the sights set - it was originally shooing pretty low and to the right. At 25 yards it was about 3" each way. I've got it shooting about point of aim now, but the rear sight is adjusted pretty far to the left. Is this unusual or could I possibly have a misaligned sight or an overtorqued barrel (a couple of suggestions someone mentioned to me).

I've had problems in the past with improper barrel indexing on Bushmasters. If it bothers you that much (it bothered me that much) you can send it back and they will make the correction.

You think that's what is causing this then? Is there any way for me to check this without special tools?

I would giv'em a call on their 800 number get and see what they say; because if it is that far out, you may want them to fix it. I have called them many times, and they are really friendly. GOOD CHOICE!

Had to have one of my Dissi uppers re-inexed. 13 days from day mailed to day returned.
I would do it.

Quoted: Had to have one of my Dissi uppers re-inexed. 13 days from day mailed to day returned. I would do it.

I may have to do that, too.
It's giving the low/right POA/POI.
Of course, I had a "gunsmith" install the Hogue forend, requiring removal of the front sight.
Maybe he didn't get it back on correctly.
If I do this, I may have the original forend and flash suppressor reinstalled to completely restore the firearm.  
Whaddaya think?

Holy cow! I sent an email to Bushmaster right after I posted here to see if they thought I should send it back. Thinking better of trying to get answers through email I was fixing to call, but they have already responded and said yes, I should send it back and gave me an address to send it to. That was quick!

BTW, I've only fired about 200 rounds through it but it has functioned flawlessly and appears to be very consistent, given my meager abilities.

This is just a thought, but are you getting a good cheek weld?
Put the rifle up to your cheek, with just the toe of the stock touching your shoulder?
If you try to sit the stock square against your shoulder, then crane your head over, you would probably have to adjust the sights to the left to compensate.
Or maybe I'm full of it.