Do you still need to use an antenna of any type,
Yes. I first used rabbit ears and those worked fine. I also have an antenna outside that feeds our whole house. It works fine, too. I just unhook the T.V. from the existing antenna cable, plug that cable into the converter box, then plug an antenna cable between the converter box and the T.V. antenna jack. Then we leave the T.V. on channel 3 and off you go. We are about 10 miles from most of the transmitters, so no big deal.
Our little T.V. is compatible with the converter box remote control, so one remote to turn on the T.V. and converter. That is nice.
However, in our living room, we have too much equipment of varying manufactures. So, here is what I did...
We have a very nice Toshiba analog T.V. I leave that on VIDEO input #1. We only use it as a monitor, now.
We have a very nice surround sound system. I leave that on VIDEO #1 as well.
We have a selector switch that works by remote control. It has 8 inputs and two outputs.
We have a digital converter box into the #1 input of the switch.
We have the satellite T.V. into the #2 input of the switch.
We have the DVD player into the #3.
VCR into the #4.
Game systems in some of the others, etc...
The #1 output of the selector switch goes into the input of the surround sound. (eventually, the #2 output of the selector switch will go into a modulator to feed back into the whole house system so we can watch anything from the living room on any other T.V. anywhere else in the house).
We have a LEARNING REMOTE that is able to control everything including the switch, except it will not learn the remote codes for the converter box for some reason. So, we are down to two remotes for all of our electronic stuff. Plus the remote operates the lights in the house over Radio Frequency.

The learning remote is the key to ease of operation.
I did talk with TV tech last week who runs a shop in my town and he was not very optimistic about the performance, said he's tried the converter and found that it's like others have said, weak signals equal no picture, so makes sense that it may be a problem in the fringe areas.
JB.
A T.V. tech thinks its O.K. to have a weak analog signal and not solve it?

Weak analog signals can be solved with an antenna upgrade, relocation, amplification, etc.... The exact same thing can be done for weak digital signals.
The payoff is the beautiful picture of digital VS analog. There is just no comparison.
