Certainly convenient, but not really up there in terms of picture and sound quality. Bear in mind that TEAC don't actually make tv's so it will be a 'badged' cheaply made set with unknown origins, possibly a Currys/Dixons 'special'. This may well cause problems further down the line compared with buying a small tv from the more prominent manufacturers.
Don't forget that an iPod stores/plays video in a fairly low resolution so won't look particularly great on a larger tv. Also the speakers on this tv are typically small-screen weak, so don't expect to rock the house if you want to use the dock to play back music.
Best thing would be to download something onto your iPod and pop back to currys and try it out. If the price is right and it does what you need, go for it.