Pole-Zero Plots Diagram Explanation I experiment with the coefficient quantization in an IIR filter. I change some values like the passband ripple and also how many bits i want for the quantization method. In the first picture i have 1db passband ripple , 'round'and 7-bits as the quantization method:



In the second picture i have 1.3db as the passband ripple ,'round' and 6-bits as quantization method.



These are the PZP diagrams. I dont understand how i can extract useful information from the diagrams in order to say which design is better or to make comparisons between these 2 designs.How the Poles and Zeros affect my decision for what is better?

edit: the images becomes bigger and more visible when you copy the url and open or select view image. Also with the green is the quantized and with blue the un-quantized coefficients.

edit2:As Matt asks for magnitude frequency response I have add the extra information:

1db passband ripple , 'round'and 7-bits







1.3db as the passband ripple ,'round' and 6-bits







EDIT: After the answer from Matt i need to add more information:

I want to find a set of quantized coefficients that meet the specification with the minimum number of bits. 
 My specification is an 8th-order IIR filter with the following transfer function magnitude response:
\begin{align*}
 0\,\mathrm{db} \pm 1.5 \,\mathrm{db} &amp; \quad \text{for } \quad 0.2&lt;|v|&lt;0.3 \cr
 \lt −60\,\mathrm{db} &amp; \quad\text{for } \quad |v|&lt;0.14\text{ and } |v|&gt;0.36
\end{align*} 

I use this matlab function:  $ [b,a]=ellip(n,Rp,Rs,Wp) , $ 

after some trials i found that (the filter is implemented using second-order sections) :  $ [b,a]=ellip(4,1,60,2*[0.2,0.3]) $  and using 7-bit quantization i take the diagram above that i think verify the specification (if i make a mistake please correct me) , 

but if a use: $ [b,a]=ellip(4,1.3,60,2*[0.2,0.3]) $ and 6-bit quantization also i take a reasonable result. My concern is if my thought and procedure is correct or i have a mistake and i need to stick with 7-bits quantization?
It is indeed hard to compare the two designs just using the pole-zero diagrams. I think it would be much more useful to have a look at the (magnitude of the) frequency responses, and compare the change of the frequency response before and after coefficient quantization. The only thing I can say from looking at the pole-zero plots is that you have designed an eighth order bandpass filter with center frequency $f_s/4$ (by $f_s$ I mean the sampling frequency).