Well, obviously everyone has their own opinions. I'd say anytime you make a generic statement about a company that produces probably 100+ different products, it will be accurate in some cases and not in others.
In regards to platform sharing, the midsize SUV is certain a case where they are quite similar. Though they do look different and have different levels of equipment. As for what GM did with Saab, it depends on your perspective. Saab was a company with quirky cars that loses money. Now with the 9-3 on a global platform, they actually have sales worth measuring. I suspect the 9-7 will help a lot too, in spite of being similar to other trucks. I don't quite see why similar is bad, though. You have 4 trucks that are similar in looks, content and price. So you can choose which subtle tweaks you prefer, and the cost is about the same. How is that horrible? Granted it's not the only formula a car company should use, though.
One interesting point was about the feel and isolation/etc of Lexus vs Toyota. In this case, what should GM do to emulate that? Make one version of their shared platform crappier so to widen the difference? This is basically what you are saying is true of the Camry compared to the ES. It is less good. Well, what if the cost difference to make the Camry nicer (sound insulation, whatever stuff you said) was minor, since they already do it? What if they bumped the Camry up to be nicer, and the ES/Camry difference was mainly about small things like subtle looks and such? Would that be stupid for Toyota to do? Should they intentionally keep the Camry down so it won't impinge on the ES? You can load a Camry up to about the same price as a base ES. What's the differentiation there then? Is this a bad thing? Or is it just a choice buyers can make whichever way they see fit?
I personally feel that keeping vehicles within the company from competing with each other is stupid, and has kept GM back for years. Make the cars the best you can at whatever price/feature point you are looking at. If it competes with an upper scale model, awesome! Just think of what a value that car is then! If Buick can make a car on an existing platform, meaning the car will be nicer for less money than a new platform, why shouldn't they? Just because Pontiac makes a similar one? The cars aren't the same, and the buyers aren't the same.
Would it be better if GM combined two similar cars into one and sold 400,000 a year, or had two different yet similar cars that sell 250,000 a year each? Look at GM's Chevy and GMC pickup truck sales compared to the F-150. The F-150 is the best selling model, but would GM be better off with that level of sales for their full-sized truck platforms? No way...
GM's midsize sedan sales are the same way. Combining them all would simply reduce sales and give them one successful "model" vs 5 models that don't lead in sales, but when put together make GM the biggest seller of automobiles in the US.
In regards to the HHR, the PT Cruiser actually sells fairly well. You can also see the double-standard here. The HHR is always picked at in auto rags for being a copy of the PT. I'd think the important thing is, is it a nice car, and is it better? Where were the similar comments when the Ridgeline came out? Aren't all japanese trucks just copies since the US was already in those markets? Does that mean it's lame or dumb? Isn't it smart business to make a new product that competes in an area another company is dominating? Maybe GM should have made the HHR sooner, but getting in that market isn't dumb if it creates sales and brings in money.
