Had some time to test the MClassic. I've tried it on PS3, PS2, PS1 games on PS3, & Dreamcast. The complaints of it 'crushing' the blacks is true, but I was able to adjust my TV & in-game display settings to rectify that for the most part. However, each game system seems to want different settings, so I ended up using three different hdmi inputs on my TV dedicated to each system, & I've been manually swapping the MClassic across the three hdmi cables hanging from the back of the set, as well as the game inputs going into the MClassic. It's the easiest way to use one MClassic & to avoid having to re-set the TV display settings for each system (if I were to use a splitter), & it sits on top of my subwoofer within easy reach, & still looks relatively clean. I still have to make a TV brightness & sharpness adjustment between 'PS1 games on PS3' & actual PS3 games, & I found that Gran Turismo 5 on PS3 likes a gamma boost between day-to-night scenarios & vice-versa, but other than that, I've made the setup in general as 'set it & forget it' as possible, with the best possible picture for each system.
My TV set is 1080p max, but if your tv can do 1440p, the MClassic can go up to that.
PS3 games see a nice little boost in graphics. Going from 720p to 1080p looks good to me. I've been testing it using GTA5, & GT5. Had to do a lot of work testing different settings to get the picture looking good, due to the 'black crush'.
PS2 - I'm using PS2 only to play SOCOM, which has an in-game option to output in 480p native, if you are using the PS2 component-out cables. Many/most PS2 games only output in 480i, which aren't going to be upscaled by the MClassic. But, it does a nice job on the 480p signal, upscaling it to 1080p. Compared to directly feeding the PS2 component to my TV, & also comparing it to the 'passthru' mode on the MClassic, it is a nice improvement. If you want to do this, you also need an A/D converter between the PS2 component cables & the MClassic, & I use my OSSC. Had to do a lot of work testing different settings to get the picture looking good, due to the 'black crush'. The OSSC setting 'Pre ADC Gain' proved to be helpful here. It seems to act similarly to the 'gamma' adjustment in my TV, but with greater range/ effectiveness. The OSSC also seems to present my TV with a signal that it likes in terms of not screwing up the aspect ratio. PS2 component directly into my TV would end up with a screwed-up aspect ratio, squishing everything vertically. PS2 into the OSSC to the TV, or even with the MClassic in place after the OSSC, & the aspect ratio is perfect. A welcome surprise.
Dreamcast - I haven't spent much time testing the Dreamcast due to getting side-tracked with setting up the PS2 through OSSC, & then testing the MClassic on that & the PS3, but I checked it out on a few DC games, & it looks promising. I'll have to spend time tuning the picture, but everything seemed to be working & looking better than before. My Dreamcast is stock, outputting to a VGA box so it force-boots everything that supports it in 480p native to the OSSC. MClassic upscaled that to 1080p & it looked really good, & I think that my TV somehow seems to like the signal better, because it seemed like some artifacts that used to show up on certain games are now gone, but I need to test it more to verify that. One other reason I haven't tested the DC as much is that audio is a pain to handle with my current setup. What I plan to do is to buy a newer OSSC, which has a better system of handling the audio chains for multiple systems. I'll be able to input both my PS2 & my Dreamcast audio into the OSSC, which will then integrate them into the HDMI-out signal of the OSSC. Right now I have to use the RCA breakouts of the Dreamcast VGA box, or the PS2 component cables, & it's a pain for me to keep switching those, so I've been leaving it for until I get an upgraded OSSC. Unfortunately my TV only has one HDMI input+analog RCA input, or I would just run another set of RCAs back there to one of the other HDMI inputs.
In general, I'm happy so far with the MClassic as a scaler & for its antialiasing functions. Although it would be nice if it had an option to shut off the dynamic contrast or whatever is in there crushing the blacks.