For a past few months, VR’s been in a bit of a holding pattern–we roughly know what the first round of consumer headmounted displays (HMDs) will look like and offer, but it could be months before we actually see how they stack up against each other in the wild.

That’s especially true of the higher-end HMDs, like the Oculus Rift, HTC Vive, and Sony Playstation VR.

One factor in determining a potential front-runner, could be the controllers those systems use upon launch.

In June, when Oculus held its press event to give details on the consumer version (CV1) slated for release sometime in Q1, 2016, CEO Brendan Iribe announced a partnership with Microsoft, and that the CV1 would ship with the Xbox One Wireless controller. The news was met with a resounding “meh” that was only saved when founder Palmer Luckey introduced Oculus Touch and the Half Moon prototype, a set of controllers with gesture recognition, finger pose recognition, hand presence, and haptics.

Buzz from demos out of E3 the following week was good. However, for all the excitement, those controllers won’t be available any time soon.

More advanced controllers will be available for the Playstation VR and HTC Vive, however, and in particular it’s the Vive that could prove the biggest competition for Oculus.

Gartner analyst Brian Blau said that the lack of an immersive controller probably wouldn’t put too much of a dent in sales for Oculus’ Q1 launch, but delaying past Q2 could disadvantage them.

Another point both Blau and Forrester analyst J.P. Gownder brought up is how the absence of the controller could affect developers and the content they create.

“The fact that they’re going to be designing the experience around the Xbox controller means that could become the track. Once developers start developing on that, the Oculus Touch offering may not be as popular,” said Gownder, adding that it could depend on how easy it is to design for more than the Xbox controller and Touch, eventually.

And, that could impact the overall experience because, as Gownder said, while the Xbox controller is good for gaming, it wasn’t specifically designed for virtual reality.

For now, developers have been using the Leap Motion sensor attached to the front of the Rift developer kits to allow users to see their hands. The Leap Motion sensor was not originally designed for VR, but has found use there, in that one of the big ideas behind it was a better, more intuitive way to interface with a computer, apart from devices like a mouse and keyboard, or what CEO and founder Michael Buckwald described to TechRepublic in September as “barrier between us and technology.”

Controllers are a part of the equation–sensors, like the Vive’s “lighthouses,” which are to be placed around a room at a certain distance–help the controllers function. The combination results in what he calls augmented virtuality–bringing a sense of the physical into the digital.

Gownder said that the Vive goes a step further than Oculus by letting users understand the contours of their rooms using those sensors, and by having sophisticated hand controllers natively built for VR.

To be sure, controllers won’t make or break success for either. Oculus has the backing of tech giant Facebook, while some are still squeamish about HTC’s health and how a major downturn could affect the Vive.

“If HTC Vive can get a foothold in the market early–and they’ll have a head start–this is starting to look like a serious competitor to Oculus,” Gownder said.