I have heard this car has a lot of service problems.

yeah...we just bought one! It is amazing. All Lexus products are pretty good. Not so much on the service problems unless you got a lemon (A brand new Car that has problems with everything)

My aunt had one and the transmission had many issues and completely went out when she had under 50k miles on it... quality, I think not.

Brother and sister both had one... they didn't have problems.