The xib compiler in Xcode 5.0.1 always sets the scaling bit of all NSViews which results in dramatically reduced performance. Until Apple fixes this severe bug, we work around this by patching NSKeyedUnarchiver to clear the bit during decoding of the compiled xib files. By the way: We filed this bug three months ago under rdar://14359398.

gistfile1.txt

@interface NSKeyedUnarchiver (Xcode5Fix)
@end

@implementation NSKeyedUnarchiver (Xcode5Fix)

+ (void)load
{
    [self exchangeInstanceMethod:@selector(decodeInt32ForKey:)
                      withMethod:@selector(xcode5Fix_decodeInt32ForKey:)];
}

- (int32_t) xcode5Fix_decodeInt32ForKey:(NSString*)key
{
    int32_t value = [self xcode5Fix_decodeInt32ForKey:key];
    if ([key isEqualToString:@"NSvFlags"]) {
        if (value & 0x400)
            NSLog (@"Removing scaled flag from NSvFlags: 0x%X", value);
        value &= ~0x400;
    }
    return value;
}

@end