I replaced my S550 2008 by the S4100. This is a good cheap product with very good image quality. It should be noted a marked reduction in size of the device as well as weight. An all-plastic construction that unfortunately becomes a standard among many manufacturers to reduce costs. This has a direct impact on the vibrations generated by this player, it's random depending on the disc but regularly seen. It is very fast in terms of reading quickness, speed accelerated too. The image is perfect and therefore brighter than my S550 details appear to the eye. We must put the camera image adjustment mode "standard" to remain as faithful as possible (gamma cheapest). It will take a little TV set to finish the color adjustment. His side it seems to me more than the old punchi but why ?? We are thus fully digital image and sound should be identical on all drives .... I think the choice of setting the internal decoding chips sound and image were made. But it is very positive! Side trips are taken is in any HDMI, again this will reduce costs and I think it is also the best choice because HDMI is needed everywhere. No WIFI and it's very good, it is less than crap in the air above my box is already. So DLNA no concern for everyone involved (TV, BD, box, PC ....). After sony services I crazy to me royally, unnecessary and redundant apps it's good I have the same on my TV (also sony ...), so double. We pay 2 times stuff that are useless. Character VOD not for me. I not buy a Blu-ray drive for watching movies in poor quality via the Internet. 3D works well but hey this is not techno nirvana (active 3D) and as I like to me, well I'm going without. Remember a good cable also to connect your TV, especially 3m. Small remote control and it lacks backlighting that I had before in handy in the dark. And we still go win a few euros at the expense of the client's comfort. DLNA works well, the GUI too. We still lack a bit of fluidity and speed (yes I know I'm picky) but there's progress. Go even an effort to reach the level of our smartphones without having a quad core!. So in the final a safe bet for a good price, it only remains to judge the reliability over time, but good by then we will surely be passed to the UHD ... no?