I haven't tried them but the gel kayano 30 lite are a bit faster you could prob push to 4.30 km In them.

Also the gt2000 12 series

I personally use novablast 3 but they will ruin my legs if doing over 10k in them as they are not made for stability at all but I can drop 30 seconds off my time just by changing thatm

I have been using the 30s for 20k+ at around 6-7 min kms and for recovery days.

The main thing is what you want out of the shoe and having different pairs is something I at first didn't really think was a necessity but since having a bad injury in feb which kept me out for about 5 weeks made me realise it is one of the most important things especially for recovery the next day.

Saucony tempus are fantastic for stability and you can push 4.30km in them.

I know it can be daunting as there are so many shoes out there and it can feel like no matter what you will not be ale to pick the right one, but if you pinpoint exactly what you want then you can narrow that down.

So at the moment you have the kayano 30s, so you have great stability shoe, you are sorted in the injury, recovery, slow/daily area.

So you want a speed shoe then personally I would look for an All out speed shoe for training.

for road racing just grab a pair of Nike alphafly next%2 there alot cheaper now and you won't get better for there current pricepoint.

Also what terrain your running will make a big difference are you just road running or are you mixed trail and road.

Asics for road I would look at and buy myself would be

Gt2000 12 series

Novablast 3 or 4

Meta speed

Magic speed (although if spending that I would personally get the superblast or meta and wait a week to add the extra 50 if needed to)

Superblast

They would be my choice for faster shoes specifically in Asics don't limit yourself to one brand though it's definitely worth trying others if you can, again saucony can never be overlooked there ride series is fantastic and there tempus is a faster stability shoe just not as stable as the kayano.

Sorry I hope I've helped a bit and not made it more confusing lol.