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I've been warned off 5" triplet apos by an owner who said they take hours to thermally settle because of the insulating air layer on either side of the center lens element. With the large temp changes we have at night they don't always work well in aussie conditions.
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I have a 5" triplet APO (FLT-132) and it takes no more than an hour to settle. I've also looked through three TOA-130s and I didn't notice any settling problems.
The temperature variations we have are much less than in many other parts of the world where many people use this style of telescope.
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I read somewhere it uses FPL-51 glass rather than FPL-53 as used in the ED80. What are the implications of using FPL-51 rather than FPL-53?
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Assuming the quality of the glass, polishing and mounting is the same, the advantage of FPL-53 is that the same degree of colour correction can be achieved at shorter focal ratios than with FPL-51. This is advantageous not only because shorter refractors are easier to handle and mount but in imaging where faster focal lengths mean shorter exposures. FPL-51 is cheaper than FPL-53.