I had the earlier model, the HDR162. The Hitachi machines are all made by Vestel, so are pretty much identical to the machines from Bush, Alba, Wharfedale and several others (most sold by Argos). If I remember your machine is based on Vestel's T825 hardware.
I understand from Futuara that the newer T835 models are more reliable, but the T825 models do suffer some niggles. The EPG and recording list slows to a crawl with a large number of timers set, prone to random lockups too. Both of these issues can be minimised by a power cycle, if your machine has a low power mode activate it as that seems to help with those models that have low power on standby (it effectively switches the machine completely off, using only minimal power). The T825's also suffered occasional stuttering on playback, sometimes a recording will jump forward by a random amount, sometimes a few seconds sometimes a couple of minutes. Thankfully it doesn't happen often. The niggles aren't down to electrical interference, it's down to the software/hardware.
Overall though I always felt the good points outweighed the occasional issue. Accurate recording was pretty much always reliable, occasionally it would miss the very start or end of a programme, but not often and it was usually just the titles. It's easy to use compared to some others and it was cheap compared to others too. At £39 you've got a bit of a bargain and can't really complain if you get the odd niggle.