Chalk it up to tempering expectations or merely a desire to shrug off competitors, but following Verizon’s announcement that it’s moving “full steam ahead” toward a 2018 rollout of 5G cellular services, T-Mobile and AT&T separately raised questions this week about 5G’s initial appeal. Though each carrier’s statements and motivations were different, they stand in marked contrast to their enthusiastic 5G announcements earlier this year.

T-Mobile has committed to a 2019 nationwide rollout of 5G services, behind both Verizon and AT&T, which have announced initial 5G deployments in multiple cities during 2018. As some 5G standards and hardware are still being finalized, the three top U.S. carriers have publicly jousted over what constitutes “true 5G” service. Verizon has committed to being first out of the gate by offering “fixed 5G” hardware for residential broadband use, while AT&T has committed to being first with “mobile 5G” by using mobile hotspot pucks, and T-Mobile is waiting on the first 5G smartphones.

Despite T-Mobile’s plan to be third to market, company VP Karri Kuoppamaki revealed that the carrier’s 5G service will likely be only 25 to 50 percent faster than current LTE, at least to start. That would be less than half of the 1 to 2 Gbps initial peak speeds promised by chipmakers and competing carriers, which anticipate 5G will start by at least doubling LTE’s bandwidth, as well as radically improving its responsiveness.

While the news was disappointing, it wasn’t entirely surprising, as T-Mobile has focused much of its energy on a nationwide rollout of 600MHz service — radio spectrum that gives up peak data speeds in order to cover huge distances. Verizon and AT&T have focused primarily on short-range millimeter wave 5G services, which will require numerous “small cells” at roughly the distance of street lamps to provide ultra high-speed, low-latency cellular service.

According to a PCMag report, Kuoppamaki anticipated that T-Mobile’s 5G will improve over time in both 600MHz performance and its deployment of millimeter wave hardware in some areas. “Initially, we didn’t see gigabit speeds on LTE,” he said, “we saw very low speeds. But today we see much higher than that. It’s kind of irrelevant what [the speed] number is going to be on day one, as it will improve over time.”

During a quarterly Q&A call with analysts, AT&T CFO John Stephens separately threw shade on Verizon’s plan to begin its 5G rollout with fixed 5G service, offering an alternative to home broadband. FierceWireless reports that Stephens described fixed wireless as neither exciting nor beneficial for AT&T, even though “our tests have shown it can be done,” he said. “We can do it.”

The reason for the attitude: Like all 5G carriers, AT&T is relying on a significant amount of fiber optic cabling as the backbone for its 5G wireless network, and at the moment AT&T doesn’t see a good reason to run fiber all the way through neighborhoods only to connect homes to that fiber with 5G wireless equipment. If “we’ve got fiber there,” Stephens said, “it may be just as effective, and may be a better quality product to give those customers fiber to the home.” Put another way, Verizon’s fixed 5G wireless service might be first, but it isn’t a big deal.

AT&T and T-Mobile both make fair points, and there’s no question Verizon’s quest to be first with 5G will limit both the scope and the value of its initial offerings to the broader marketplace. That said, whether their 5G service is “first,” “fastest,” or “most widely available,” healthy competition between carriers is likely to be a good thing for 5G consumers, whether they buy in this year or wait until late next year for the dust to start settling.