Review: Samsung Rugby III for AT&T
I tried AT&T's "EPTT" in a local AT&T store, coincidentally in an area with no LTE service yet, so it was operating on the 3G AT&T network. The performance could only be described as "push-to-wait...and then some". Initial PTT "setup times" on four different phones they demonstrated for me were on the order of ten seconds to establish first connection. When you're accustomed to Nextel's average connection times of one second or less, AT&T's 3G PTT might not cut it for you.
True 4G "EPTT" might be faster, it certainly should be, but even if you are in a 4G-LTE area with AT&T, the Rugby-III is not LTE-capable, so it will never be able to take advantage of any potential 4G EPTT speed increases. You'll have to buy a genuine LTE phone that is also PTT-enabled if you expect to take advantage of 4G PTT when it becomes available in your area.
I don't know if all of AT&T's 3G coverage has PTT as slow as what I experienced, but if you are coming from Nextel and you are considering AT&T for PTT, make sure you try it out in YOUR real world, don't take AT&T's ads or the sales person's word for it. Nextel is still by far & away the reigning champ in terms of PTT performance. Sprint's CDMA-based Direct Connect is pretty darn good, almost as good as Nextel's, IF you are in an area with strong 3G "data" signal on Sprint's CDMA network. Verizon's PTT (also runs on the data portion of VZ's 3G network) is fairly consistently fast, but it is so feature-poor compared to either Nextel or Sprint's current PTT offerings, and the "chirp" sequencing & logic is not the same as Nextel's & Sprint's, so be sure you give VZ's PTT a thorough real-world test, too.
- Re: AT&T PTT? by Eric M. Zeman