When recording onto DVD, or recording from external sources on the AV inputs, you have to use the regular XP, SP, LP and EP modes. We checked these out and the resulting picture quality is every bit as good as that of the DMR-EX79 - crisp edges, a distinct lack of block/mosquito noise in XP and SP, smooth movement and sharp detail. And thanks to the Blu-ray burner on-board, you can fit hours and hours of SD stuff on a single disc, which will particularly delight DV camcorder owners whose high-quality home movies will no longer be restricted to one hour (you can fit over five hours on a 25GB Blu-ray disc in XP).
And as a Blu-ray player, the DMR-BS850 performs brilliantly, with picture and sound performance that lives up to the lofty standards set by the DMP-BD60 and BD80. Hellboy II's mesmerising mix of fantasy characters, intricately detailed scenery and breathtaking set pieces is reproduced with the sort of mind-blowing clarity and depth you hope for from the format, thanks largely to the presence of the UniPhier chip.
Once again the knockout combo of P4HD and PHL Reference Chroma Processor Plus technology deliver the goods, not only with Blu-ray but with DVD - the BS850 also does a fine job of upscaling standard-def discs to 1080p. Blu-ray disc loading times are reasonable - Hellboy II's Universal logo fired up 53 seconds after pressing close on the disc tray, but it also had to switch from Freesat to Blu-ray mode within that time, which is quite impressive.
The deck's ability to output DTS HD Master Audio and Dolby TrueHD as a bitstream or convert them into PCM means you can get sensationally sharp and involving multi-channel sound out of it, provided your amp has an HDMI input (there are no multi-channel analogue outs). The high-quality sound components (similar to the ones found in the BD80) also do a pleasing job with stereo CDs and MP3/LPCM audio from the hard-disk.
Judged purely on its technological merits, the DMR-BS850 is a truly astonishing piece of kit. The wealth of features and recording functionality on-board beggars belief, but it's testament to Panasonic's knack for user-friendly design that it never feels overly complicated or uncooperative. The inclusion of twin Freesat tuners, a Blu-ray burner, a huge hard-disk, bitstream recording, MPEG-4 compression and extensive editing features mean that the DMR-BS850 has no equal as a recording tool.
But of course it's not for everyone. If you already own a Sky+ HD box, rarely archive programmes on disc or aren't satisfied by Freesat's current HD offering, then this isn't the product for you. And there's no getting away from the fact that £1,000 is a lot of money, restricting the product's appeal to affluent techno-heads.
But let's throw that price into some sort of context. Groundbreaking technology like this is always expensive - just look at Panasonic's first DVD/HDD recorder and Blu-ray player, both of which cost £1,000 at launch. And don't forget that the BS850 is so much more than a recorder - it's also a comprehensive multimedia hub and a top-notch Blu-ray player, which means that you certainly won't feel short-changed if you do fork out for one.