Well, after watching a couple movies with my new S350, I gotta say it might be my favorite stand-alone so far (I have had a Sam 1400/1500, BD30).
The Menu setup is nice (just like the PS3 with the XMB), unit powers on fast and exceedingly quick with the fast power on option.
Unit itself is actually very compact, about 3/4 the depth of the 1500/BD30's, same width and about the same height as the BD30.
No noises when doing disc searches/loads (1500 made a very noticeable motor noise). I will say that the 1500 does seem to start play quicker and I did not time the S350, but kids wanted to watch enchanted last night (Good cause I wanted to check for TrueHD drops anyways). The little chipmunk with the 1500 tapped his head 8 times or so and the S350, IIRC was about 11 times (hows that for scientific analysis). Btw, not a single TrueHD dropout on my onkyo 606.
Family even commented that colors seemed better with the S350 and over all PQ was better. Also, remote control response was great for me.
One nice thing I noticed and I'm not sure how it works yet since there is not a firmware update out, is that the player will automatically check for firmware updates and alert you to them if you connect the player to your network. After my experiences with Samsung, I am a bit more confident in Sony to get proper and timely firmware updates out. That was biggest reservation when I sould my BD30 for the 1500 was that samsung has a problem with updates and are very slow to address issues.
Oh yes, the player does not get hot to the touch like the 1500 did. I am really thinking that is what caused my 1500 to take a nose dive.
Anyways, there are lots of deals out there with many people getting the S350 for around $300 so look around if you are interested. I got mine from Amazon.