Ok after watching BD movies all day long.

I finally put in some SD DVDs, to check upconversion (did a A/B test with Rocky (part 1).
It's a good thing there are people like me, that are truly neutral.
Did not even bother testing it against the BD-P1200, because it was not even as good as the XA1. (and I know the 1200 is better than the XA1)
So yeah, I did a A/B test with the player that was setup in the same room (XA1).
My best estimate is the PS3 falls in between tha HD-A2 and the XA1.
So with the current HD players I have here now, here is what would be best for SD upconversion.
1. BD-P1200
2. HD-XA1
3. PS3
4. HD-A2
5. NeuNeo HVD-2085 (not a HD player, but just an upconverter - to 1080p)(I keep this player, for the VGA d-sub connector, in case I use strictly for a computer monitor or projector with limited connections)
6. (placing at #6, because I have not tested yet. The X-box HD DVD player)
In the case of the Oppo (that I do not have), my best guess is that the Oppo is a much better SD upconverter (specially considering that it was made just for that purpose). But the value of the PS3 certainly outweighs the Oppo. Considering a new Oppo is roughly 240.00 shipped, and is only good for SD DVDs.
The PS3 is a good upconverter, I have installed the latest firmware (well, I used version 2.0 updated from version 1.92).
But I find the PS3 is not top of the line (by no means), it is much better suited for BD playback and gaming, as well it is great as a limited HTPC.
I am debating on returning it, because Brandsmart has the BD-P1400 for 299.00 ATM (with 8 free BDs).
The good thing with the PS3, is its other uses, for storing (and playback) of your MP3 collection, and MPEG2 clips, as well it is excellent for photos (thats not even mentioning the gaming aspect of it)..
So it is a toss-up, on what is more important to you, PQ or usefullness (specially if you plan on gaming with it, which I don't).
I'll give it a few more days of testing, and see if the vast amount of features are worth it to me.
Considering I already have some excellent upconverters, I may just keep it for the HTPC aspect of the console.
Compare pictures by all means can be posted, but it may not show in pics the difference I am looking at.
Using the XA1 as example, it (XA1) has a very slight softness to it, without losing any detail of the upconverted image, with clear film like quality. Where the PS3 loses slight image quality, with oversharpnening, and seems to lose depth of image by slightly crushing blacks (contrast levels).
This is with the PS3 upconvering to 1080p, to a TV that is full 1080p capable, while using the same exact calibrated settings.