No no no - Tiguan in US has NEVER had a DSG. I think you are confusing it with the Taos which does have a 7 speed DSG in the 4Motion models.
For OP - the VW is going to have lower service costs if that is an important factor. The CLA is their budget model and it feels as such, had a couple as loaners when I drove MB's. They are not the most refined vehicle and top of the line models from non-luxury makes (Mazda 3, VW Jetta, Acura ILX, etc.) are better and cheaper than the base model CLA's. You pay for the star in the grill and thats about it.
For reference I went from VW's to MB and am now back at VW. I honestly could no longer justify the marginal increase in feel/driving for the massive price in purchase and service, you pay for that star.