I have just some totally horrible experience from an SMSC product. It was an integrated MAC+PHY. The product was basically unusable, I worked trying to get it work for months and never got it running reliably. It was a huge waste of time. And I was just porting something I had done earlier on DM9000A, which was order or two orders of magnitude easier.
The SMSC part was complex as hell, with documentation worse than many Chinese datasheets.
Emulating an I2C interface by writing "clock" and "data" bits to a configuration register, only to access more configuration registers, is something so poorly designed that I wanted to cry. I understand why they did it, but having a huge burden of history on your shoulders because you only glued some random old designs together quickly to release a "new" product, means you cannot call it "integrated product" or well-engineered.
They may have better products in their portfolio, and maybe this was a single failure, but I'll never want to use LANxxxx anything. If nothing else, I still get shivers from the name alone.