I have got one and don't regret buying it, however it is only a peace of mind back up to complement the navigation techniques taught during your PPL.
I agree with T & R you must develop your normal navigation techniques, both VFR & Radio Nav before regularly using a GPS.
Think of a GPS as a nav back-up system. Similar to carrying a transceiver in case of radio failure.
I have just 4 subjects to go in the ATPL writtens & in both Gen Nav & especially Radio Nav the GPS (GNSS) is becoming a larger part of the course. The rumours are NDBs will go within 5 years & some VORs perhaps within 10.
If your hour building will involve touring, for example around Europe, it may be a wise investment.
Once I was flying over the English Channel from Ostende towards Caen & told by Lille to report abeam Abbeville. No problem if you can see the town but I was up to 40NM away @ 4,000ft, Europe in summer can be hazy. I could have triangulated the VORs & used the coastal visual references and compared them to my map but the modern cockpit is there to relieve unnecessary work, I waited for the wing of my little aeroplane cursor to point to Abbeville on the map, then reported.
When asked for a report at a predetermined distance & no DME is available a GPS receiver will tell you accurately how far to go & when you are there (assuming it is working properly), leaving out the worry of accuracy as a low hours pilot can have in a busy controlled airspace. Once you have a licence you are a pilot in the eyes of the ATC, whether 50 hours or 5000 hours (unless you comment on your low hours on the flight plan).
None of this detracts from the fact that you should do very precise flight planning with your maps, plogs, wizzwheel, nav aid info (Radio & Nav Aid frequencies) and plates (VFR or IFR) for both destination & en route diversions, the GPS is not as good as a Jeppessen plate for all the aerodrome detail.
If I remember correctly the GPS is still not a primary navigation aid for light aircraft so if you got into trouble you must still show your calculated flight plan using all the above mentioned items to an official.
My personal opinion is if you are not going to fly more than 150 miles away from home base, don't bother.
You must consider several facts before buying the GPS;
1, Do I have the cash & the budget for it?
2, Will I be flying very long distances, eg as I have done, Jersey to Rome Urbe in a PA28?
3, If I buy one, what do I like the look of?
4, Is it easy to read in turbulent conditions?
5, Is it easy to use?
6, Is it easy to get data upgrades? How much are the upgrades?
7, What is the power supply? How long will batteries last?
If you decide to buy a GPS it is very much your own decision.
I have used only Garmins so cannot comment on Magellan or Skyforce. I have used the GPS195 (I own one), GPS Pilot, GPS 295 & the built in GPS 430.
I personally would go for the more simple black & white models firstly, I think the colour is a gimick for us mere mortals. That leaves the 195, Pilot & the new 196.
If buying a new one today I would consider the 196, good memory and a nice big screen. The Pilot for me is too small for a quick glance to reinforce your positional beliefs. If your budget is smaller I would consider the 195, it still has more processing power than the Lunar Module, from the Apollo missions, fairly cheap now and a nice big screen
As I said these are my opinions & it is up to you.
Good luck in your decision making.
Enjoy your flying.
FB
PS: Heard a rumour, not sure if urban legend or not, of a PPL a few years ago, that declared a MAYDAY because his batteries on his GPS ran out. The CAA were not very happy & 'did' him.