A luck factor is of course present, but appears rather low in good players, because with so many trains at any time benign or less follow suit well-fitting stones. Especially if the field is already somewhat developed some thing always goes, no matter what you get on the hand, so that the allowable knockback and Neu-pulling of stones (which it indeed is in Scrabble) rarely if ever needed. The tactical decision which stones are also used when not always easy - I put the red diamond now that the upper left corner, where it also forms a 3- and a 4-series with pre-set stones and collect right now ordinary 7 points or keep I prefer something else, because there are already 4 diamonds at the bottom right in a row, the red would be the 5th and if I may a few moves later a yellow diamond draw (which is not yet available, so if the opponent no obvious has 3 times is in the bag) then there's a Qwirkle (completed 6-series) and 12 points ...
Go to particularly good for two games and also does not produce aggression because no tactic component for targeted sabotage or destroy the opponent's play is present.
Conclusion: Qwirkle has in my opinion the makings of a classic - the best newcomer in our game closet for a long time. Simplest material and rules, great fun. If you like Scrabble, Rummikub Genial and who will love also Qwirkle.