Okay, I see not much help on this forum anymore for new ACER owners or prespective owner so I will try to help. As a disclaimer, I have an ACER H5360 which I've used with a PC for excellent 3D (and 2D), while maintaining a Mits H3800 (1080p) for just 2D. I have since sold the Mits and bought an Optoma HD3300 (1080p) for both 2D and 3D. (The ACER is currently up for sale in AVS classifieds.)
That said, the ACER is an excellent first choice to get into 3D when using a PC or going through a converter such as the Optoma 3D-XL--medium priced but good reviews, Viewsonic VP3D1--which I have used and relatively cheap and the VIP Theatre-expensive but lots of features. For 3D, the ACER is typically chosen over rivals such as the Optoma HD66 for it's perfect 3D image, color pop, and brightness--but that's arguable.
It works with DLPlink shutter glasses as well as nVidia 3D vision. Each has it's following. For DLPlink, which I like, 3D Heaven shutter glasses work great (and they are cheap) as well as Optoma and others (google search).
For PC, you'll need a nVidia GT500 series based card for nVidia 3D vision which is great for gaming, or an AMD Radeon 6000 series based card for dlplink, which is great for all-around viewing. Also the latest drivers. Check the early part of this thread for information how to set that up--also check out the Optoma HD66 thread for good info as well, since lot of what needs to happen at the PC end applies to both projectors.
For screen type to maximize 3D enjoyment--most 1.0 gain screens will work up to 120". The more screen gain, the better for 3D since the glasses reduce lumens more than half. I use a DIY 142" 1.3 gain screen and it looks great on that. For outstanding 3D brightness, many buy a Dalite High Power screen--the screen is retroreflective meaning the light reflects to the source, so it's perfect for table mounted projectors, however it will work with ceiling mounted projectors, but the 2.4 gain reduces to about 1.4-1.8 depending how low from the ceiling the projector is mounted. I do NOT recommend any grey screens or screens less than 1.0 gain. While they do justice to 2D images (e.g. increase black levels), they will cut light gain too much for 3D.
For screen size and projector distance: Best to use this calculator (also info in the manual which you can download--ftp://ftp.acer-euro.com/projector/h5360/manual/H5360user_enu.pdf
You'll see for a 120" screen, 14' is about max distance. 23' would not work for that screen size--the image would be about 194" diagonal.
The projector, when mounted to the ceiling is required to be upside down, so that the keystoning is reduced. If mounted right-side up on a shelf near the ceiling the projector would have to be tilted down with lots of keystone. Reason being the image on these projectors and most theater projectors is offset from the lens so the bottom of the image when projected is above (or below if ceiling mounted) the projector--see the manual for offset information.
As for 2D content. It compares ok to other 720p projectors for the price, but don't expect miracles. When used in low-lamp mode and correctly adjusted for contrast and brightness, it's quite nice. Problem is most people adjust for maximum brightness and high-lamp mode for 3D, and this makes 2D pretty unwatchable if you like film-like contrast--but again this can be adjusted.
You'll find for 3D, the resolution looks higher than 720p--it's a mind trick when combining two 720p images that are slightly different for each eye and the black levels look okay. You can select different gamma levels, which will give you the best black levels and contrast through the menu--see manual.
As for audio/video pass-through a 1.4 receiver. Best to get a receiver that others have tested that works, or you take your chances, and there is a way to fake a PC into thinking it's seeing the receiver as a projector but requires a PC registry update I think--best left to those who are really into tinkering with their PCs. Getting the ACER (or any other 3D ready projector) to work with a PC is going to be frustrating if you are not a PC nut willing to try things and do registry updates, etc. (as I've found out).
For PC software to watch 3D blu-ray, check out PowerDVD Ultra 11 from cyberlink, and Total Media Theatre (TMT) 5 from Arcsoft. These are the two that are used most. I've had the best luck with TMT 5. It can be hit or miss, though, depending on how your PC is setup--and that journey is a whole other discussion. In the end I recommend you get a 3D blu-ray player and a converter rather than a PC, IF
you are not willing to tinker and spend many hours getting your PC to work
--you've been warned.
Also, don't confuse the ACER H5360 3D ready projector for the ACER H5360BD 1.4 compliant projector with the 3D processor built-in--it's only sold in Europe these days and never made it to the US market.
Also, when the projector is mounted properly, overall focus is excellent with slight differences between the center and the outer parts of the image, which is normal for this projector lens. If you are experiencing non-uniform focus from one side to the other, then the projector is probably not aligned correctly with the screen (e.g. mounted off to one side). This will also make one side fo the image appear wider than the other.