Wow, excellent replies, thanks everyone !
Inbound I will just take my lumps - I have a free day Sunday so no impetus other than tiredness to get to my hotel.
On the way home, I fly back to KUL on the Monday morning from PEN then have a 10 hour connection. So I will leave my case in storage at KLIA and head into KLCC again but will make sure I'm back at the airport about 3 hours before departure.
Really starting to look forward to it now
P.S. Great tip on the Grab Taxi app, thanks