Smartest money you can spend on an upgrade is to wait til October, we will know by then what the situation on Zen is.
I would bet that right now AMD has a bunch of engineering samples that they are trying to exhaust in internal benchmarks against Intels Skylake. What they do not want to do is put themselves in a position where they retail a cpu and then get independent reviewers testing their new Zen and finding that it only keeps up with a modest core i5 or something of that sort.
The i7 skylake is really the target for AMD, they should be aiming for Zens peak performance to be about on par with IPC to the latest gen i7, after that they can tweak and under-clock each core if they want to match i5 and i3 pricing thresholds... I suspect right now that Zen has just not reached its plateau in their tests and they are nervous that the market of enthusiasts and hardcore reviewers might view the new FX AM4 product as 'not quite good enough'.
I have no doubt personally that AMD will produce something good, but the gap between intel and amd for architecture has been significant over the past 5 odd years... and it is a bold move for AMD to try and bridge that gap in one big swooping overhaul.
The ARM investment was not a bad idea either this might have added some engineering competence to AMD, and might allow for Zen to pull out a few surprises from an architecture perspective.
In terms of how their new CPU's shape up, they did the right thing with the APU range, an APU focused on the mainstream market that does not require hardcore performance but can run most day to day tasks effectively and be priced affordable for the masses was smart business. But I wonder if this move has helped AMD turn their attention to the performance market now.
Realistically what we want to see in AMD products is a clear distinction from their 'mainstream' cpu offerings and their performance ones. We have to demand that their price / performance ratio warrants the extra spending of perhaps a few hundred dollars on a CPU. Intel successfully managed this, you can visibly see the performance differences in an i5 vs lets say a Pentium G4400 or something like that..
With AMD we want something similar, and for benchmarking types they want to see realistic and quantitative affirmation that the binning process for all Zen CPU's offers a consistent level of performance a significant improvement in IPC and also a much lower thermal and power consumption overhead.
What to buy right now is limited to mostly intel stuff, you can pick low budget to premium budget intel based parts which all have support for the latest standards and a builder can basically put together a system that will be upgradeable on any type of budget.
AMD needs to stop milking the AM3+ FX range now, they need to make an aggressive move to lower the prices of the existing range of FX cpus to clear the excess stocks and then focus all their attention on a smooth but urgent release of Zen.. the market will not wait forever, we have heard about Zen and actively been hyping about it since late 2014, we do not want to see it run into mid 2017 for any real commercialization, they have said October this year as far as I know, so if you really want an AMD rig then hold out a few more months and lets truly see what AMD can do to bridge the gap between them and Intel.