Newbie here.
I bought my 991.1 C4S three months ago, and have rarely used Sports Plus mode - I realise it's best for track use - but on the few occasions I have 'experimented' the pdk gearbox is reluctant to change up unless or until it hits c.7,500rpm, meaning I'm still in second gear at illegal motorway speeds.
Of course I can override it with the paddles, or switching to manual mode, but just wondered if this is normal behaviour for Sports Plus mode?

 

That’s normal on the .1s. In Sport+, it will only upshift at redline in auto mode. Sport+ in auto mode is designed primarily for track use

 

Shifts are close to red line, and when it does shift you should notice it shifts harder and gives you a good bump going into the next year. It's awesome.

 

That's totally normal.

My unsolicited opinion? Don't use Sport+ in D on the street, it's completely unnecessary and, frankly, annoying to other motorists and pedestrians. It's more intended for track use. Fortunately, if you're carving canyons or doing other probably-illegal public street stuff and using Drive instead of Manual, Sport will do just fine as it will downshift very early for you when you brake heavily for a corner so you can power out of it without having it have to shift mid-corner.

I believe 4k RPM is the minimum rev range Sport+ shoots for before shifting, which makes sense because you want to be up in the peak power band as much as possible on the track.

The sporty street-friendly behaviour you're probably wanting is what you'll see in Sport, not Sport+. Still firm chassis (if so equipped), still shifts faster than you need it do, and hangs on to gears a little bit longer all without keeping you on the right half of the tach at all costs.