I have lifetime Titanium, and I use the United Silver to get E+ seats 24 hours before the flight. I got two exit row seats on my last two flights, and I had an entire exit row to myself for one of the flights. On that flight with the entire row, I saw the flight attendant tell another flight attendant traveling that he could not sit in the exit row or economy plus since that was considered an upgrade.

The best thing about silver besides E+ and the occasional upgrade is that you have some elite status so you can check one bag for free on domestic flights of up to 70 pounds and you get same day change (SDC) on flights for free. You also get priority during irregular operations (IROPS) when things go wrong. You are behind higher elite customers, but you are ahead of general members and non-MP people. This can be especially helpful on flights with few elite customers.

I am not sure if elite customers in other star alliance carriers have the same status if they are star alliance silver for IROPS, but I assume that would be the case.