To shoot in the leather as quickly as possible, I like to dampen the leather with a little water before I shoot it the first time. Just a few seconds under a tap (or under your drink bottle if you're at the range!), and the tab will dry out within a few ends of shooting, leaving a nice string groove. The leather can sometimes sound a bit creaky when you are first shooting it in - don't worry! It's perfectly normal, and the sound will go away in a short time. Not everyone experiences this, I find it varies from one draw hand technique to the next.
The leather shoots in quickly, meaning that it is MUCH easier and faster to replace the leather of your tab than with a cordovan face. You don't have to worry about changing your much loved tab and taking weeks or months for it to soften up - you can have it ready in a day, so replace the leathers when they need it!