Faster updates is a mixed blessing and a matter of personal preference.
When you get Android updates first, you sometimes get bugs and confusion first. For example -
http://phandroid.com/2014/11/05/battery-draining-wifi-bug-could-be-delaying-android-50-lollipop/
Updates are not as important as they used to be.
Today, most of your key Android services runs through a separate module called Google Play Services. Unlike the old days where you needed a full update for the equivalent of that, today Google just pushes updates to that from the Play Store.
And the latest version of Google Play Services means that you can run the latest versions of the major apps, even if you're way behind on Android.
That's a huge departure from the old days and the way Apple still does it, requiring people to update their whole iOS operating system. (Side note, they've done a great job marketing how fast they get updates out, but there's a better way and Android does it now.)
So - if you like running the latest Android (for any reason, no big deal what floats your boat) and you're OK with a trimmed down user experience out of the box, you want a Nexus.
If you want almost as trimmed down but just a little behind the Nexus for the update schedule, and a few extra hardware features, you want a GPE.
If you don't care about the fastest update schedule and want a really rich user experience right out of the box, you want the standard Sense version (and for example, the standard Sense version is getting the Lollipop / Android 5 update within the next 90 days from HTC, plus or minus what your carrier adds for testing).
A lot of people know that I always shop the other brands, get excited and then buy the latest HTC I can anyway. My friends, here on the forums and out in the world enjoy poking fun at me for that and I'm way ok with that - if the poster boy for HTC shoe fits, wear it.
But let me give a few non-fanboy examples of what I mean by richer user experience with stock Sense.
I use Exchange ActiveSync email for work.
Many apps claim to support it and you can buy specialty email apps specifically for it.
And nothing holds a candle to the Exchange ActiveSync support built in to HTC Sense - fact, not opinion.
I like a nice clock / weather widget and I like a really good news reader.
In a way, those are trivial because there are a lot of great apps for those things. And when I look at the creativity some people show on the "show your home page" threads here, I'm really humbled, I just don't have that flair. And I've chased a lot - if not all lmao - of the news reader apps out there. Again, lots of excellence, flexibility
Blinkfeed, part of Sense, is made for people like me. It's built in, does a great job as a unified clock, weather and news widget and it just works, not complicated and looks good. I customized my Blinkfeed feeds for my news preferences, my wife didn't bother and she's completely happy with her news. Because time and weather are a swipe away on the homepage, no more need for extra widgets there.
I even mixed mine up with a different launcher than stock Sense, she didn't and neither of us miss out on the big easy button for features. Because we can rely on Google Play Services updates to support our apps, we just don't care about the latest Android.
If you're like that, you want Sense, because there are lots more examples like that.
If you don't care about things like that and enjoy the fun of customizing your own stock Android experience (anyway, I think it's fun, I've done that too) and you want to know that you're getting the whole Android update enchilada ASAP then you probably want the GPE.
Sorry I can't give a better answer to your question - I'm just trying to give an honest answer despite my bias so you can decide what's right for you.
You asked about GPE, and I had to explain Sense so I could explain how GPE is different.
If a GPE fan checks in, no doubt they'll be able to give a much clearer answer.
Anyway - hope this helps.