The first Evo V I had was perfect, as far as the GPS. It found me right away, always followed me, pinpointed me to a pretty small diameter, no lag, no issues. But I ordered a replacement for a different problem (now I wish I'd kept it, for that GPS), and the new phone had problems with the GPS. I had them send me yet another phone because of that, but I have the same GPS problems on the replacement replacement.
So I'm not sure what it's related to. It does seem to be a bit better after the recent system update was completed, but I have no idea if that has anything to do with it. GPS is a major consideration in a phone for me, since I use it a lot, and I won't (knowingly) buy any phone that doesn't have it working. That's part of the reason why I never bought the Triumph. Try the A-GPS Injector app, some people seem to have some luck with that.
I am happy to report that the 1 day I had trouble has been the only day I've had any trouble. Every time I've used the phone since, the GPS has grabbed a lock quickly and held-on tight & fast.
I am not saying that I NEEDED to do this, but what I did: I wiped the phone clean, and then after re-setting it up I also performed the "Update PRC" and "Update Profile" actions. Since that time, it has ran rock solid. It also helped me to remember that the Kyocera Rise I had been using up until a month or so ago, although its GPS typically worked very well, there was one occasion one-time where it couldn't get a lock to save its life, I had to pull over at a gas station & place it on top of their air pump (for inflating your tires) and leave it there aimed straight at the sky while pumping gas before it FINALLY obtained a lock. It had never done that before, and it didn't do it again after then either.
A tip: one app I like to use is "GPS Status." The reason: it shows LOTS of information such as your elevation, speed, there's a compass, and perhaps most of all--your GPS coordinates. As a side-note, I REALLY wish people understood GPS coordinates and used them. They are GREAT. They allow you to specify a difficult-to-find location precisely on a map (Google Earth, a Garmin Nuvi etc) and enable someone to GPS their way straight to it, even if the address doesn't come up right, and without those ridiculous "turn on the 2nd right after the house with the yellow plastic cow in the yard" types of directions that NEVER work right. I have used it whenever I've found interesting sights while out & about, or especially last year when we went on a vacation & I wanted to be able to "bookmark" my favorite places to where I could easily return to them later without getting lost & frustrated, and it has been great.
I can't count the number of times someone was trying to tell me where something was & insisted that a GPS couldn't find it because the address didn't come up properly, they'd INSIST on those "turn right by the windmill you can't miss it" directions, and when you asked them "can you get the GPS coordinates" their reply "no, I told you, the address doesn't come up on a GPS correctly." No, I didn't ask for the ADDRESS, I asked for the COORDINATES. "I TOLD YOU, it doesn't come up on a GPS." Even UPS can't get it right, they lost a package of mine because they couldn't find me and when I asked them "can you do GPS coordinates" they didn't even know what that was. Ugh.
As for the Motorola Triumph--I heard that. That has to be the worst phone I have ever used. Some have said if you root it & do this & that, it works fine--rooting is fine, but I shouldn't HAVE to root it for the GPS to work half-right. One time it took half-an-hour--HALF AN HOUR!!--to find my location. It was all I could do not to smash that phone into a million pieces. I sold it to someone who said they didn't mind the GPS behavior (I made a point that they make sure they understood that the GPS was HORRIBLE on that phone) and I spent that money on an LG Optimus Elite--smaller screen aside, it was a far better-acting phone.
Now, FINALLY, I can have a phone with a screen 4" or larger that also has decent GPS on it. Third time's the charm I suppose.
