I assume you mean Time Capsule as a router b/c TM is a piece of software... I am very pleased with the TC as a router. I have my COMCAST cable modem connected to the TC and then the TC serving as the wireless router for my small business setup with 2 Macs and 2 PCs. I also have a Cisco router in bridge mode connected to the C b/c I use Vonage VoIP service.
Everything was just plug & play. Only issue I had was with The Vista PC but that was a firewall issue I quickly fixed. Also NAS drives are tricky to setup if those drives were formated and assigned logical addresses with a previous Windows Network.
If you read the manual before setting up the network and do the proper settings for file sharing, printer sharing, network name, passwords, etc you will probably save 2-3 trips to the forum to figure out things.
Good luck