We purchased this television after looking at other Sony LCD and Panasonic plasma models (G10, S10). Even this higher end V10 is less money than a comparably sized LCD by several hundred dollars. I chose this model over the S series for its networking capabilites and the G series for its 96Hz 24p film mode.
Picture quality is superior to my Sony LCD, with deeper blacks, vivid colors, and great off-axis viewing. I generally stick with the "standard" and "game" picture settings. The display seems more responsive than my LCD using my PS3 for games, however it isn't a good choice for gaming (due to image retention, see below). THX mode also looks good with Blu-ray movies - not too dim, but perhaps a bit too green.
The 4 cooling fans mounted on top of the unit are fairly quiet, I don't notice them. Our LCD does better in rooms with more sunlight and sound quality also seems better on the Sony overall, but the Panasonic may be more detailed.
Unfortunately, there are two important negatives I've discovered. I am now having issues with "image retention". Video games with static images, e.g. health icons, leave faint shadows weeks after playing! This is most noticeable displaying a blank screen, e.g. selecting an unused input. Hopefully they will go away over time, but I am disappointed and in hindsight wish I had known this could be more of an issue with today's plasmas. Also, the Viera Cast Amazon Video on Demand feature is sluggish at times - I've read Panasonic may be having trouble keeping up with the server load. Perhaps the TV needs a larger memory buffer.