I see post where you've decided to pass, but for some more info, the 4200, as your description states, is a DCII receiver. Most "FTA" receivers are DVB receivers. A DVB receiver can't get DCII, and a DCII receiver can't get DVB.
I have 2 4200 receivers, and there are a number of free channels that it can receive. You could call them FTA, or they might be better described as FP and/or ZK. A brand new 4200 can only get ZK, however a used 4200 which has at one time been authorized for any service, can also get FP signals. So it's better to get a used receiver, since it's not likely that you'll be able to get a new receiver authorized.
Another issue is that there are at least 3 different varieties of 4200 receivers, maybe more. I have a 4200V and a 4200b model. The 4200V will do all the common SR values. The 4200b and 4200c models only do something like 3 different SR values. Many of the DCII signals however, use the 19510 SR, which both these models have, but they won't do the 29270 or a few of the lower SR values. So I can't recommend getting a b or c model unless you're only interested in a few specific feeds which have the SR rates available.
Some might recommend getting a 905 or 922 4DTV instead, which is fine if you're going to subscribe to pay services, however for free channels, the 4200 is capable of getting some signals that the 4DTVs cannot get, specifically channels using frequency/SR combinations not available on the 4DTVs.
Anyway, the 4200 is not a replacement for a FTA receiver, but IS a compliment that will give you a few extra channels, however I wouldn't pay too much for one. My original 4200V cost me over $1200, however I think I paid $40 for my 4200b. I wouldn't pay more than that, because DCII channels have been getting more and more scarce. I hardly ever use either of my receivers anymore, because most signals have shifted to DVB.
Actually, the limitation you refer to is that it only holds one VCT (virtual channel table), not that it only holds one transponder. When I first got my 4200, I think there were about 5 or 6 regular PBS transponders, a GPTV transponder, a LPTV transponder, and 2 SCETV transponders, all on the two nearby sats, T4 and GE3, and I THINK they were all on one VCT, although it may have been two VCTs. I have it written down somewhere. Later, things got separated a bit, and GPTV and SCETV and LPTV were on one VCT, the 5 or 6 PBS on another, and later T4 died, and SCETV moved to T14, but there were always at least 5 PBS transponders on that main VCT. Another more recent example is the NET channels on G28. Up until very recently, when their DVB service took the place of one of their DCII transponders, you could receive both NET transponders on one VCT. Also, those HITs transponders that used to be on G7 (I think), were all on one VCT, and that was like 12 different transponders, and not only that, the VCT would also work on the C-band hits channels up on C3.
The thing is that with the 4200, you tune in a VCT by locking on one transponder, but after the VCT is loaded, when you change channels, often the receiver is changing to other transponders.
But yes, now, at least most DCII signals that a 4200 can pick up are on VCTs that only cover one transponder, but I think there are still a few multiple ones. I forget what sat the HITS things went to, but I'd bet there were still multiple transponders on the single VCT. But the one VCT limitation is one reason that I stopped using the 4200. It was just too much trouble to switch from one VCT to another. I think I counted something like 50+ keystrokes and a wait of several minutes to tune in a new VCT.
Some of the more modern commercial DCII receivers that hold more than one VCT have a disadvantage though, and that is that it may be necessary to know the VCT number in order to tune in channels, whereas the 4200 automatically loads the VCT and loads the channels when you tune one of the transponders in the VCT. So I guess there are good points and bad points about holding only one VCT. Also, the 4DTVs, that don't even use a VCT, are dependent on channel maps that are uploaded via sat, and I'm not sure what is going to happen when those subscription services come to an end. It's possible that the 4200s will still be used, but the 4DTVs will be boat anchors.
I would recommend a Motorola DSR-4800 (or the Digitrans 7100/7150, which are basically rebranded Motorola DSR-4800s) if you are interested in Digicipher II. These will get both ZK and FP out of the box, no activation needed. They will also receive DVB, and in the case of the Digitrans 7150, DVB 4:2:2. They are broadcast-grade receivers, and are built very well. They will fit in a 1 rack unit space (1.75")...