Non binary LDPC codes are promising error correcting codes which have increasingly raised interest in the last few years. This paper addresses some comparisons for short and moderate blocklengths between binary and non binary LDPC codes from different points of view, including error correction performance, complexity cost and possible adaptation and optimization opportunities. It shows a performance advantage of non binary codes up to 0.5 dB when only using GF(4) instead of GF(2), and up to 0.75 dB when using GF(16). Despite the large additional complexity induced by non binary decoding, these codes are very promising since adapted complexity reduction techniques are already investigated and show interesting results. Some analysis on decoding behavior of non binary LDPC decoder is also given in this paper. Such comparisons and analysis are interesting to gain insights on non binary LDPC codes and to derive guidelines for their optimization.