I was impressed most in this series by the new ball skills of SRL pacers. This SAF attack actually isn't what it was in past and couple of their stalwarts are living on their past glory while Olivier cashed on PAK batting to be honest. If Rabada doesn't click, SAF will struggle to get a side all-out twice effectively. In this series (& the PAK one as well in 2nd & 3rd Test), what I have seen is their lack of penetration in 2nd innings without the extra "zip' from typical SAF tracks.
SAF wickets are a bit different - it's a sort of mixture between AUS & ENG. AUS tracks are hard & bouncy but it's heartless for medium pacers for lack of green grass while ENG tracks are green, but softer to bang it in therefore apart from top blocks, we have seen two different types of bowlers doing well in two different countries. SAF tracks are hard & bouncy, but it has green grass as well and being at the tip of continental cape, wind is much stronger in SAF, and 3 of their venues are at the highest altitude among Test venues .... all this makes it a fantastic destination for any type of pacer.
BUT, what it still needs is discipline by new ball, hitting right length and making new ball play, which SRL pacers did brilliantly and they kept SAF in check always - if not by wicket, but kept the run rate down, so that batsmen don't run away with the game; later pacers came back with multiple strikes. There is only one 5for by a spinner and I don't think any pacer had a 4for either, but all 3 stuck to their task brilliantly and they did get some bonus wickets from Dimuth's gentle pace.
I think, this is probably the biggest difference with PAK & SRL here. SRL bowled first both times and went to first lunch in commanding position; PAK bowled first once and SAF raced to like 170/1 at probably 4+/over. Also, SRL picked a genuine finger spinner who turns the ball (guy had like 125 FC wickets in 21 games!!!!) and bats at 11

, and SAF has always been weak against SLAO spin. In terms of batting, apart from first few overs, SRL always tried to keep scoring at a good rate, which can't happen with Azhar Ali at 3 - Babar & Shan were positive, later Asad as well and they did score some runs, but it was the bowling that was really depressing.