It'll depend on how well corrected it is, you may see some CA, but I suspect Skywatcher have been choosy with their glass types. This is not the first ~70mm doublet on the market, so I'd be surprised if they haven't nailed it.
You will need at least a field flattener to accomodate an APS-C sized chip like in the 600d, though. The same is true for most small refractors, besides the ones that have it built-in, at significantly higher cost.
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