The Samsung Infuse 4G has 4G right in the name, but it's more of an AT&T misnomer than actual 4G phone (or worse, part of the propaganda machine).
AT&T has no true 4G, not yet anyway, and we weren't able to clock more than 3Mbps bandwidth speed anywhere but San Francisco, where we were able to hit 9.6Mbps down and .67Mbps upload - once. Suffice it to say, that's not great for what's being touted as AT&T's first unit with HSPA+ Category 14 speeds.
It's faster than most other US 3G speeds, and certainly nothing to squawk at, but not nearly as fast as we've seen on Verizon's LTE or even T-Mobile's own HSPA+ network.
The browser is the same we've seen on other Froyo devices. Like Chrome, typing a single word into the address bar will perform a Google search, and gestures feel as natural as ever - whether you're pinching to zoom out or two-finger tapping to zoom in.
Like the Messages app, there's also a speak-to-text feature, but the microphone icon's located in a different spot - up near the address bar. It's the same spot the bookmark feature is located, though the bookmark feature disappears the second you tap the address bar.
Resolutions top out at 800 x 480, which is the same as most new Samsung Phones. However on the big screen, it can feel a tad bit low while surfing certain sites. Fonts specifically didn't look quite as crisp, and sometimes sites felt a bit cramped.
Every once in a while, sites will "crack" when you scroll from side to side, displaying a line of text cracked in half, displaying at different heights. But fortunately, this problem wasn't frequent and didn't persist. Any issues we had were easily fixed by quitting and relaunching the app.