Heres what the NTSB found regarding glass cockpits in light aircraft.
http://www.avweb.com/pdf/ntsb_glass-cockpit-lsa_report.pdf
Its not exactly "safer" from an accident statistic standpoint, although this little slide show is far from complete, it presents some data on the subject
Old steam gauges have worked just fine since Doolittle took the first intentional instrument flight. I am of the school of thought that a traditionaly equiped aircraft with a GPS is just as capable as anything with a glass panel AND since there are no accident statistics to prove that the glass cockpits enhance safety, I feel that the argument over which is "better" doesnt really matter! I look at it this way; the information you recieve from a G1000 is the same as you get from the good old 6-pack, its simply displayed better... other than that, what does it do for you?
Of course it is much cooler to have a G1000 in your 172 than the old 6 pack, but youre still gonna go 100 knots and get there in the same amount of time