I personally dun see so good prospect for mxlxk or pxxdxrxxx... Like I said, the glory period has been over.
skudai area is as old as tebrau also... so around the same....
Here's my little hypothesis on the history of Bukit Indah, Tebrau and nearby areas:
1. Bukit Indah is about 15 years old.
2. Tebrau is rather large, and I think the Tamans developed along Tebrau Highway over 30-40 years by spreading upwards from the city center towards Jalan Pandan, then eastward along Pasir Gudang Highway, judging from the age and density of the buildings.
3. Molek/Ponderosa/Johor Jaya should be about similar age of 20-30 years.
4. About 15 years ago, probably at the peak that you mentioned (i.e. congestion and high cost of housing), the developments sprang north of Jalan Pandan. So Mount Austin belongs to this era of around 15 years ago from the more modern design and layout of the buildings, and Desa Tebrau and Taman Gaya started to develop around 10 years ago after Mount Austin became successful and expensive.
5. Bandar Dato Onn, Seri Austin, Setia Indah, Setia Eco Cascadia are very recent developments around 5 years old or less driven by the recent Iskandar boom.
Molek still has many banks and eateries. Probably the houses and residents are older (which is about right if the new residents shifted there in their 20s, they should be in their 50s-60s now), which is why the areas seem more toned down. However I think the old rich are staying around this area.
From what I gather at other forums, the buyers (probably children from Molek/Ponderosa/Johor Jaya in their 30s-40s) are looking for newer developments 5 km radius centered around Mount Austin (including Bandar Dato Onn, Seri Austin, Setia Indah, Taman Gaya). These are affluent people with high buying power (perhaps supported by their parents living nearby), which could be the reason why Desa Tebrau $2 mil+ RM bungalows were mopped up by the locals within months of launch.
Please let me know if I'm right or wrong. I really need to go down to take a closer look at Tebrau. I suspect the latest development now should spread towards Senai.