Many people have jumped to P3D and never looked back.
I think whether it is 'better' will depend on your system, your settings, your add-ins, type of flying you do and your expectations ... but as a general sweeping statement, 'Yes', I think most people would agree they feel P3D is 'better'.
Having said that, there is a huge amount of change coming in the flight sim arena over the next 12 months with some major titles ramping up from scratch, or with significant updates so while I'm never really one to say wait and see (because there is *always* something coming) ... in this particular instance, you might want to. Of course, if you have an older system that might need replacing to run a new not-yet-released modern sim, gaze into your crystal ball and see whether that is a factor in your decision making process.
No-one. And I mean *no-one* can really advise you whether to change because, as stated above, it will depend on your system, your settings, your expectations, add-ons, type of flying you do, etc, etc. There is only one person can make that call ... you.
Lockheed Martin do provide a refund policy though, so you can always try it and then return it if it isn't everything you expected.
-- Jeff, Rolleston, NZ
P3Dv4.x and a bunch of add-on stuff... some 'global' products, but otherwise NZ-only