Chains are way easier. I just lube mine about every 1k miles and I am good to go. I just put my third chain on my GSX1100 and I am sitting at 58K miles. So 29K miles per chain that cost about $150 sure beats having a Final Drive go south for $1200 to $1500. Plus you can change the gearing a lot easier. I went for a smaller sprocket set, to get better mileage as I do mostly highway driving at speed.
I too had the gear shift # on my R1100GS, but I do not miss it on the Suzuki. No need to figure your speed, you will be able to just hear when to shift. I can still tell with my earplugs in and my music playing in my helmet. It is just something you will get used to, just do not over think it.
That tach is messed up, but that is what they make rev limiters for. Unless you feel like taking it apart to change, or modify the plastic inlay for it, your probally stuck with it.