100 lbs more weight is not going to make the GSR Sedan lose a race against any LS. And as far as insurance goes, the engine is what kills you. You might get a break getting the sedan over the coupe GSR but your insurance will be higher than an LS because of the motor. Trust me. My insurance went way up when I got my GSR and I had a Mustang before. Just to give you an idea...

My 99 GSR- $529.70 per 6 months

My 99 Accord LX- $348.60 per 6 months

Keep in mind that I'm over 25 years old and married. I pay about $140 per month for the both of them. Getting married is where its at if you are looking for an insurance break. When I turned 25 my insurance went down a whole whoppin $1.50 per month. I was paying $160 per month being a single male under 25 years old on my Stang. I got married, sold the stang, got a GSR and my insurance on both cars was less than I was paying for the one. How screwed up is that?