Yes, I would Definetly recommend buying a Sat Nav. I purchased a Tom Tom about 6 months ago..(Tom Tom XL Europe), simply because I was living in mainland Europe at the time. I found it an incredible advantage not only to finding your way easily to your destination but as a previous person stated, a HUGE safety benefit. Not only do you no longer need to look at a map, but you can almost totally forget about needing to look out for road signs and just concentrate solely on other road users whilst listening to spoken instructions.
I found that especially beneficial at night or in poor visibility/heavy rain, when it's difficult to see some road signs.
As for not necessarily needing a Sat Nav system whilst travelling on a regular road journey that you are familiar with, they are indispensible if you need to take a side road etc, due to roadworks etc, immediately recalculating your route, and advising you of the next turn you need to make.
Prior to purchasing the Tom Tom, I had used a friend's MICHELIN system, which whilst good, it seemed to be about 4 or 5 seconds behind where you actually were, so as you approached a motorway turn-off that you are meant to take, it sometimes gave the turn off instruction a little late in my opinion. The Tom Tom does not suffer from that "Delay".
Finally, I'd also recommend spending the extra few Euro on the European version, simply because you can bring it with you on holidays to Europe , put it the hire car , and not worry about trying to find your hotel etc etc.
