Investing in world-class front end gear is not as exciting as getting a new instrument... but (IMO) there's not a better investment you can make.
Everything recorded thru it will sound better.
DI electric bass is a good example.
Thru a typical inexpensive front-end, DI electric bass (especially passive) often sounds weak/thin.
The same instrument running thru a Neve preamp suddenly has "it"; requires little to no EQ... and just a little compression to seat it in the mix.