PSIsCrappyDevice

gistfile1.m

BOOL PSIsCrappyDevice() {
    static BOOL isCrappyDevice = YES;
    
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        size_t size;
        sysctlbyname("hw.machine", NULL, &size, NULL, 0);
        char *machine = malloc(size);
        sysctlbyname("hw.machine", machine, &size, NULL, 0);
        NSString *platform = [[NSString alloc] initWithCString:machine];
        free(machine);
        
        isCrappyDevice = !(![platform hasPrefix:@"iP"] || [platform hasPrefix:@"iPhone3"] || [platform isEqualToString:@"iPod4,1"] || [platform hasPrefix:@"iPad2"]);
        
        [platform release];
    });
    
    return isCrappyDevice;
}

It's usually not a good idea to explicitely check for STRINGS for a platform. Much better to search for aspects. You want your code be future proof.

While checking for strings might not be a good idea, checking for aspects might break as easily. While it might never happen, just imagine the next iPad having neither Retina nor Camera, or a new device falling into this category - checking for aspects breaks and treats this device as a crappy device.

How high are the odds for apple DOWNGRADING from retina? If so, it sure must be a crappy device ;)
But true... neither is perfect.

Not all current devices have retina, so I wouldn't consider it a downgrade. There might be room for a cheaper model of the next iPhone/iPad, and we never know the specs. There's definitely neither of the methods perfect, I'm just not sure what's easier to break (so which method I should add to iOSKit :) ).