I'll take a shot at answering your question. Please note that I am not an industry insider. What I have learned I have pieced together from publicly available information during my own search for the "perfect notebook". I have concentrated my attention on manufacturers and vendors who offered the type of notebook I was looking for: a Centrino laptop with ATI 9600 graphics. I can't promise you that every bit of information and opinion I give is 100% correct.
Taiwan-based ODMs make 70% of all notebooks worldwide. The other 30% are made by Korean manufacturers such as Samsung and LG-IBM and by the few name brand computer companies who still make some of their own notebooks such as IBM and Toshiba. Of the 70% of notebooks made by Taiwan-based companies, 75% of these are actually manufactured in mainland China. The Taiwan-based ODMs have other factories in Taiwan, the Philippines, Malaysia, and Mexico.
The best websites to get information on the Taiwan-based ODMs are
www.digitimes.com and
www.taiwanhightech.com. Taiwan High Tech used to have a page called "Bring on the orders" that was particularly helpful in finding out who made laptops for whom. Unfortunately, they recently deleted that page (under legal pressure?). The major American computer vendors seem to do their best to hide who they buy their laptops from. They seem to want to maintain the illusion that they make them themselves. The American computer vendors seem to be afraid that the Taiwan-based ODMs will bypass them and sell directly to the U.S. market. As hollowed out as these companies have become with nearly everything from manufacturing to customer support contracted to other companies in other countries, I think their fear is well justified. They are rapidly becoming little more than a brand name and a marketing campaign.
The four biggest Taiwan-based notebook ODMs are Quanta, Compal, Wistron and Asustek (ASUS) in that order, though Wistron and Asustek are nearly tied for third. Other Taiwan-based ODMs include Uniwill, Arima, ECS, Clevo and MSI. Acer is a Taiwan-based integrated computer manufacturer and vendor who makes most of their own notebooks and buys some from Wistron.
My opinions about the quality of various ODMs are largely based on my opinions about the quality of the notebooks that I know they make. For example, Dell buys their notebooks largely from Quanta, Compal and Wistron. Compal makes the Inspiron 8600 and its Latitude equivalent for Dell. My opinion of the 8600 is that the quality is out of control. It's a crapshoot whether or not you get a good one. The trackpoint buttons rarely work, and it has a real heat problem when equipped with an ATI 9600. On the other hand, Compal also makes the Compaq X1000 and HP zt3000. I would consider these notebooks to be average to above average quality.
By comparison, I have a very high opinion of Wistron based on the notebooks I know they make. Wistron makes Dell's small notebooks, which I believe include the Dell 300m and 600m. From user experiences, these notebooks seem to be quite reliable. Wistron also makes the X-series ThinkPads for IBM and at least some of the R-series ThinkPads -- also reliable with good build quality. I have been impressed with the build quality of the Wistron-made Gateway M505. Even the basic AOpen laptops made by Wistron and sold largely to the Chinese clone market seem to be a good value for the money. I don't think that it is a coincidence that Dell and HP/Compaq are planning to switch their 15.4" widescreen notebook production from Compal to Wistron in the 4th quarter of 2004.
I know less about the laptops from Quanta. By process of elimination, I suspect that they make the Inspiron 51XX and 1100 series for Dell. If so, then my opinion of their quality would be low. The Inspiron 51XX series in particular is known to have severe problems with overheating. Quanta also makes laptops for HP and they make the older Gateway models.
It seems to be a very difficult task for notebook manufacturers to build a notebook using a desktop CPU and keep the heat under control. Whoever makes the Gateway M675 seems to have really mastered this issue. Unfortunately, I don't know who that is.
Clevo makes notebooks for Sager, ProStar, Eurocom, Go-L and a number of other vendors. Clevo seems quite good at making reliable notebooks with desktop CPUs, though they have somewhat less of a handle on the heat issue than the M675 manufacturer. They have earned a devoted following among those who want the highest performance notebooks without regard for weight or battery life. I have not been as impressed, however, with what I have read about Clevo's Pentium M notebooks.
I have limited information on Asustek, but from what I have read, their laptops are just as good quality as their motherboards.
ECS, known for high volume/low cost motherboards, seems to have a better reputation for their laptops. They make the VoodooPC m460 and several barebones laptops that are well regarded.
Uniwill makes laptops for Fujitsu/Siemens which are known to have particularly good screen quality. Uniwill also makes the Area-51m for Alienware.
When HP/Compaq bought their laptops from Arima, they apparently developed a reputation for bad quality. Since being dropped by HP, Arima has seen its sales and market share drop like stones. Arima has signed a deal recently, however, that has the potential to shake up the notebook computer industry. They have agreed to supply notebooks directly to Walmart that will be sold under a Walmart brand. This agreement is the first I know of where one of the ODMs has contracted directly with a U.S. retailer, thus bypassing all of the U.S. computer brands and vendors. A sign of things to come?
If anyone has corrections or additions, please send me a private message.