I think you have the question reversed. If you are after better signal to noise the MX 113 is a much better unit. It has much lower distortion, too. What it doesn't have is the flexibility of the C-11. Though variable tone controls give you more choice than the stepped controls.
I had a few friends that had 113 with 2105's and 2120's. Their systems were very listenable. The tuner section was good, too. It just didn't have enough inputs for me and why I had a C-28.
We sold 113, 112, and 114 to folks who wanted to keep it simple. Tuner, turntable and tape deck. Some stuck with their tube amps, but 250's and 2505s were most often the MX113's mate. A few times it was 275's to drive 70 volt distribution systems through out a home, where the MX 113 was the Zone B controller receiving a signal off the main system. C-28 or 26 for instance.
In one home the Mx 113 would be left in the tuner position and the tape out would feed the C-28 master pre-amp as a tuner. Then the C-28 would feed the tape out to the MX 113 tape monitor input. That way the 113 was controlling the back ground music speakers through out the house could either choose radio or the feed from the C-28 tape out with out each other effecting the volume. The second MX 113 fed the cabana, pool and tennis courts. The third fed the patio area and out front for Christmas Holidays. There was a separate system in the billiard room, and the lady of the house had a separate system for the family room and kitchen driven by the above C-28. So she had control of the entire house ex cluding the billiard/ game room and a separate system in the master bed room that received a feed as an auxiliary choice from her C-28 or the Billiard room. Here again the MX 113 was in control. I used Altec modular line amps for long 600 impedance cable runs between the M Bed room, Family/kitchen, and Billiard room. The MX 113's worked very well for a long time. The last time I checked the system was in the 90's and it was 20 years old at the time and was only in need of control cleaning and new tubes for the 275's. The 2100's, 2105, MC 75's and 2505 were all working like a charm.