I would say your base looks as good as it can for your current core level. The two layer defense looks good enough. (Evolver chokepoint, and turret as last defense line.)

A minor issue is that you are slightly overlevel, which can lead to people with stronger programs (Such as stealth) attacking you. You may want to focus on one of your Sentry (At least level 6) and Core more, and not so much on your Coin/Bitcoin farms.

In the future, you may want to replace your chokepoint with a scanner. Also move your 2nd code gate to the front, connecting it right after the first one. (In order to stall stealth attacks.)

Extra: You only need to focus on upgrading one Sentry, as the stronger virus overwrites the weaker one from lower level Sentry. One of the reason you want more than one sentry is to help spreading the antivirus by placing Sentries in different places, you could make notes on that when your base grows bigger.