The Pioneer Elite BDP-HD1 Blu-ray player and the Sony BDP-S1 appear to be almost identical twins, or at least very much based on the same technology. The reviews and comparisons of these high quality players have revealed same components being used and identical performance, while the Pioneer has a few more advanced features and a more stylish piano black design. Based on Pioneer's statement, they are manufacturing their own player while Sony has sent out a comment that they have used Pioneer components in a device designed by Sony. Either way, the both players have received rather good reviews, but the Pioneer comes with a +$500 more on the price tag.

Commencing set-up made clear that there were more similarities between the BDP-HD1 and Sony’s BDP-S1 than just the rear panel, as the two share identical on-screen instruction graphics, looks, placement and some fonts. The open drawer revealed the two players use the same disc drive as well, leading me to ask a Pioneer representative who builds its player. I was assured that Pioneer builds its player, including the drive, which makes it clear that Pioneer also builds Sony’s player.
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The Pioneer’s updatability via the internet is a big plus. All other current players require you to wait for it to arrive via mail. While looks are subjective, the HD Guru prefers the Pioneer’s more conventional appearance. Add the Home Media capability and two-year warranty (double that of competitors) and for many buyers, the $500 price premium ($1500 retail compared to Sony’s $1000) will be well worth the added expenditure. The Pioneer Elite BDP-HD1 earns the top HD Guru rating.

Source: HDGURU