linux boxes are A LOT more powerfull than standard boxes, but, they also have a near vertical learning curve. once you get used to one though, youll never go back.
how much are you looking to spend? DM800 (original) and vu+ duo are £400. DM800 clone around £200 and TM800 £250
if you want to be able to record one channel while independantly watching another, then only the VU+duo can do this, the others can record and watch from the same transponder only
between the original DM800 and the clone, ive read so many threads about people having problems with clones, personally, i wouldnt bother with one
the TM800 hardware is bombproof, but, the software lets it down (at the moment), this 'should' hopefully be sorted in the next 6 weeks, making it a cheaper contender to the DM800 (original)
If you want reliability, forget the clone, if you want twin tuners, its only really the Vu+duo, if reliability and price limit your choice, its the TM800
i won a DM800 (original) and TM800, and have had a Vu+duo for a short while. the 800's are more than ample for my needs, and if i had to choose between the 2, the price would be what decided for me, and id go for the TM800
BUT, the software is'nt quite there yet if you like to tinker with things, to just watch HD telly, its fine