I have both Vanguard and Fidelity and manages my Mom's flagship relationship with Vanguard.
For total service, great web access and processing, and overall more reliable backroom services, Fidelity is a hands-down winner for me.
Vanguard managed to completely screw up my Mothers account when they shifted to a TOD system for beneficiaries last fall. They dropped off beneficiaires, changed relative "shares" and overall left a mess. Since my Mother has a Flagship relationship, there is a designated account rep. When I could get in direct contact with her (usually a couple of days elaspe) the Vanguard rep did a reasonable job but was incredibly limited by Vanguard bureacratic processes and lock step requirements. Vanguard tends to want hard copy primary information to manage many of the personal elements whereas, Fidelity will let you do them directly on your account once you are logged-in. Without question, Fidelity's website is easier to use and has more resources. I can easily find and purchase bonds and CD's. In the Vanguard site, you need an advanced course in "query' mechanics to even find what is available. When you do buy, forget about "low cost"
Another example of Vanguard absurb mechanics is their email communications. Even at the Flagship level, the email does not actually go to your designated rep until it has been reviewed by some vetting group. Their involvement seemed to add 2-3 days to any process and the more complicated the longer.
If your needs are all mutual funds, you don't do much research and are only interested in the absolute lowest expense ratio, Vanguard is for you.
If you want customer oriented support, lots of breath, very competitive pricing ($8 trades if you are Gold, 15? with 100K), you get a whole whole lot more IMH from Fidelity.
nwsteve