A SERT is something you can do one your own but no real reason to do it if you are not changing any engine components. Yes it is possible to get the bike to run a little bit better than it does right now but you're not likely to achieve that without a dyno machine and an exhaust sniffer. Also agree the power gains would not justify the expense.
If you're not changing parts I'd try the Nightrider wires. For about $100 you get a little richer afr that should lower running temps and posiibly give a little bump in power.
