Jumping the gun a bit here but I have one of these coming from the EE....
I have fingered a few of these and have plans of making it an EDC..

I have seen complaints that the ejector is glued in rather than pinned.... Should this concern me for reliability?  Anyone drilled and pinned theirs in?

Any other reliability mods I should consider?  

I am finding holsters for 3 inch model but not the 4 inch.  Since this is scaled down,  I would like a made to fit holster rather than running a compact 1911.  Any suggestions?  

Thanks.

I had a few problems but I have to admit it was the ammo.  Use real good ammo for the break in, the chamber is tight.  No failures since the first outing.  Again I admit it was the ammo.  Beautiful gun, nice and slim for concealed carry.  Keep us posted on the search for a holster.

I have the EMP4.  The ejector is glued just like most of the other Springfield 1911's I've owned.  I've gotten mine so hot shooting steel that I had to stop and put gloves on.  I figure it the ejector does start to move I will call Springfield and have them take care of it.  So far mine shoots everything I run through it without issue.  The only thing I have done was put some Stoner grips on.  It has quickly become my favorite pistol to take to the range.

I think holster wise you should be fine with a 4 inch barrel holster like for a Springfield Champion or Kimber compact.  I have read that the grip is the main size difference.  I just measured my Metro Arms Commander and my EMP 4 with a caliper.  The widths of the slide were within .01 of each other.  The height of the slide from the dust cover to the top of the slide and the height of the slide from the back of the trigger guard to the top of the slide were within .02 between both pistols.

The only holster I have to try is a Safariland ALS for a 5 inch barrel 1911.  Both the 4.25 in Commander and the 4 inch EMP 4 fit.  The EMP 4 is a little more loose.   Probably not a good judge for fit.  David

Ejectors are glued, but no problems with my SA guns.  When they pop up, your slide will start to hang up.  Call SA for a call tag to get it pinned on them.  That would be a good time to have some mods done in their custom shop, because it's shipped on their dime.  Their CS is top notch.  

In rotation, I carry an EMP 9mm 3", or a Sig Ultra Compact 3.3" 9mm in a Comptac MTAC slide model.  The holster is IWB and has no problems with 4.25" barrels like my Sig Traditional Compact or a 5" TRP.  Most comfortable holsters I own.  That's actually my preferred IWB holsters for all my guns.  More so than the Crossbreed Supertucks.  I've owned those too.  Can't stand the metal cross bands, thin leather, and you need the combat cut.  The kydex was not that snug, causing play with the gun, causing extra finish wear on the top of the slides.  Yes, I know that it's a IWB and the belt tensions the gun to your body, but there was still play in the fit.

Use good quality ammo for break in.  NATO or +P velocity.  Stay away from underpowered offerings like UMC, white box Winchester or some cheap remanufactured ammo.  After break in, go for it.  Always drop test your carry ammo into your barrel.  They should drop in and drop out freely.  Good time to see that the ammo fits and is not long compared to the barrel hood.    

EMP dimensions are mainly in the grip girth, everything else is the same as a standard compact officer's size frame, or commander length slide.  The slide, dust cover and part of the trigger guard is all that matters in the holster "fitting."   Everything else is above the holster (i.e. grip girth, hammer, grips).

My EMP4 had a couple of FTE issues at the beginning but fine since. I carry mine in a Vedder Lite Tuck that is made for compact 4" 1911's w/o rail and it fits perfectly. And I put VZ Grips on it.