Inspect engine valves?

Your list is sufficient for discussion. Thank you.

Only when you conveniently lump all variations of "mechanical lifters" as equal. The advantages of the variations have already been reviewed. You forgot. Seems that the motorcycle arena does not concur with your opinion. Upwards of 10,000 rpm with shim over follower has been the norm since the advent of the crude KZ900's back in the early 1970's. I might add those engines had shims that were very close in dimension to the Toyotas you listed. The concern expressed by the "tuners" is with regard to valve float which is addressed by both valve spring tension and cam lob shape.

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By "lifter" you must be referring to a push rod engine where the hydraulic lash adjuster is incorporated into the cam lobe follower. If you mean two separate parts, the hydaulic lash adjuster and the associated rocker arm, then say so. Pricing for selective followers vs. shims is also high in BMW. Surely there are more examples where this is true. Why this is, I'll leave you to speculate.

Earlier to make your point, you chose to fabricate component costs at the manufacturer level. Now to make your point, you fabricate prices at the retail level. Most of us know retail prices are based more on popularity than manufacturing costs. But how often are these components replaced? I would ask you to revisit my earlier mention of my old Geo Prizm which has yet to need a single valve shim at 330,000 miles.

It seems that there are really only two possibilities -

1) The valve train is as good as you claim and routine valve checking / adjusting is not needed. However, Toyota continues to include routine checking / adjustment in their maintenance schedules. Therefore Toyota is screwing their Customers by requiring unnecessary maintenance that can cost the Customer hundreds (and possibly thousands) of dollars.

2) The valves do actually require routing checking / adjusting to avoid expensive engine damage. If this is the case, Toyota is screwing their Customers by not adopting a simple, cheap, and mature technology that the vast majority of car manufacturers adopted long ago.

Either way, Toyota Customers are the loser. There is no upside to sticking to solid lifters for a non-high performance street car. If Toyota was using solid lifters on a high performance Supra, well I could understand that. But on Camry? Come on Philip, it is not defensible. For that matter, most of the rest of the civilized world has moved away from timing belts - another expensive routine maintenance item on many Toyota engines. I suppose saying your engine has a timing chain and hydraulic lifters doesn't have the same sex appeal as saying "variable valve timing."