Some of the convoluted arguments in this thread have got my eyes glazing over .... but have answered the question. Yes you do need a GPS, it should be simple and easy to use with a moving map, you should be conversant with it and you should be equally conversant with all the other means of navigation at your disposal and as current as you can be in all of them and rely most on the one least likely to fail, with the others as backups to remain safe.
However that's no reason not to add my bit.
For example 1st time from Fairoaks to Sandown. Take off from EGTF fly south to A3, turn right, follow A3 to M27, head for Gunwharf Quay, after Gunwharf Quay head for Ryde Pier. After Ryde look for Sandown. Can see Bembridge, cannot see Sandown. Quick consult of Pilot 3 ... shows it's 3-4 miles in my 10-11 O'Clock. Know where to look, make the call, aha got it, fly circuit and land. Use of complementary technologies makes life easy without over reliance on either.
On return Depart to over Ryde Pier then dial MID VOR to go direct (but VFR). Once on track check with Mk1 eyeball and GPS. This ain't right !! Going roughly correct way but not exact. How is VOR tracking this far out ??? revert to GPS, map and eyeball to over Midhurst Town then by eyeball, heading watch and map to Dunsfold.
When have time to think as aeroplane location precisely known, return to problem .... thick t@*t ! using Ockham Freq, not Midhurst. Solution - do IMC rating and learn morse code. Again complementary technologies.
The thing that scares me most is the thought of using GPS alone and having absolutely no clue if it packed up - a place I ain't going. By all means use the best kit available, just make sure you aren't caught out when it goes t*ts up. Do gross error checks by another means. By all maens use the best kit available
coz it'll make life easier and may even prolong it one day. (I had my rear fog lamps on this morning and when I fly I'll have the transpoder for the same reason.) Just have another life prolonging plan available for when the first one goes to rat s$%t.
It's like somebody once who had little concept of mathematics telling me that 100 / 20 was 4.803 coz the (duff) calculator said so.
Years ago there was a 747 took off from Heathrow bound for the middle east and after t/o (on 09) they set the FMS and it turned left 45 degrees. The old boy in the LH seat pointed it back the right way, (lets get on our way and we'll sort it out later) but the lad in the RH seat turned it back saying the FMS must be right, the old boy had the heading for DVR confused. After some words were exchanged they returned to Heathrow on the basis of FMS u/s. At vast cost they discovered that their first way point wasn't Dover, per the plan, they'd somehow got Clacton.