Just doing a Google search for the XT60 & it's easy to read through a LOT of various forum threads/posts/reviews about those connectors since they've been out for at least 4-5 years now. There are a lot more positive things said about them, than there are negatives, & there sure seems to also be a lot more Deans converts moving to them & liking them, then it seems there are Deans converts that were unhappy for making the switch to using them.

Of course, just like the Tamiya vs HL debates/opinions, if someone is happy with a product, & it works fine for what they want, then they have every right to support it & stick with it. Deans have been very popular, reliable, & a highly recommended & accepted connector for a long time. The one sure benefit of the Deans over the XT60 would be it's slightly smaller size if you want a reliable, but smaller plug. Still, the XT60 has grown in popularity & a strong following over the last few years, & by what a vast majority of those converts point out, it does seem to have some benefits over using the Deans.

So besides all the front side connection points being fully enclosed, the selling points that a lot of people also mentioned about the XT60 compared to the Deans connectors they used, were that they are easier to solder, easier to connect together, easier to grip to disconnect (though a few had said the opposite here), & had less sparking during connection than Deans plugs.

So if you have a ton of Deans plugs on everything & have been happy with them, it wouldn't make sense to change, but for those of us who are just starting out, & do not have a lot of plugs that would need changing, I doubt you can really go completely wrong getting any of these 3 connectors.
I already ordered the EC3 connectors for myself because I like the fact I can solder the wires to the pins with the protective case removed, & everything can be done in a way where there are no exposed ends & no need for any heat shrink wrap, so no XT60's or Deans for me .... at least not for a while!
I say go ahead & get those XT60 connectors Dan, then let us know how well or poor they end up working for you!

~ Craig ~