I have a modified thompson DHD4000 and im quite happy with it.
(i pulled the orginall 40gb hdd and replaced it with a 160gb, although it only sees 138gb of the drive but that still amounts to 75 or so hours of recording)
never tryed series linking (not sure if it can do it) but to record you just highlight what you want on the EPG and then press the red button and it sets a timer to record it
. There also a facilty to set a manuall timer just in case the EPG data is missing.
It uses the 4TV epg which gives 14 days of listings, only downside is it means the DVR wakes up at 3am to get the EPG updates (its in my bedroom so on the odd occasion its woken me up before although i usally sleep right though it
) not sure if that would messup any recordings that were set to record at that time
