Fred Renzey has a nice quick explanation regarding the advantage that surrender provides on page 165 of "Bluebook II":
"Surrender is a BIG asset to the card counter, yielding an extra 0.20% to 0.25% in multi-deck play. It also lowers your volatility by smoothing out the "bumps". As a result, you can bet a little higher while running the same risk of ruin. Just exactly how much bigger you can bet depends upon whether you bring your daily stake, your trip stake or your entire bankroll into the picture."
In a nutshell, Fred then throws out some numbers . . . he states that if you never, ever, play anything but surrender, you can bet 20% bigger on the same total bankroll. As an example, a "would be" $25/hour expected win rate becomes $34/hour on a 4 hour daily stake, $35/hr on a 25 hour trip stake, and $39/hr on a 500 hour bankroll. Hope this helps.