Even though they are heavily marketing the "ultimate collectors series" thing, I feel like TLG isn't targetting collectors anymore with these sets. By collector, I mean a person who expects a model which is the absolute best possible representation of a Snowspeeder in Lego, regardless of the cost (within reason). I feel like this model is not the absolute best possible representation of a Snowspeeder. That's not to say it isn't a nice model, but there are some obvious points that could be improved. Collectibility also implies exclusiveness / scarcity, which will not be the case for this set at all. Maybe my definition is wrong and they are going for a different type of collector or even completionists.
Now I still think this is one of the best looking Star Wars sets out there. I think it looks better than the old one, though maybe it just looks more "modern". In any case, I don't have a 10129 so for me it's great.
But I would have been happier if they did something new. There's only about 26 UCS sets so far, so it's kinda silly to have two duplicates already. If they keep them coming at this rate, we'll have a new Falcon, Y-Wing and Star Destroyer in the next five years. Meanwhile they could release AT-AT, A-Wing, Nebulon, Venator, Republic Gunship, Sail Barge, ...