Some objective opinions:
1 - 22K - 23K is OK if you really love Toyota, only can drive an automatic car and have owned a lot of Toyotas in the past. Personally, the new XRS with 22 - 23K puts it right in competition with the Civic SI sedan, which offers far more value for the money especially considering the race-bred K20 RSX Type S performance motor with an 8000 rpm redline. I like the styling of the new XRS more and the fact that XRS is easier to drive around town with much better torque, but the SI is more bang for the buck in just about every other category. Although, similar weight of close to 3000 pounds, but it makes 40 more HP and has aggresively geared 6 speed manual. If you can drive a 6-speed manual, highly recommended to check out the Civic SI sedan for the same money.
2 - Toyota stereo systems are generally very good. I would say around 200 W PMPO output. My stock 7 speaker stereo system in the 2ZZ-GE XRS trounces the upgraded 6 speaker stereo system in my friend's loaded Civic EX. The upgraded one should sound very nice without a doubt. You should not worry much about the stereo system.
3 - Just because one owner had to switch out the auto tranny does not mean it has a bad tranny. 2AZ-FE and the automatic transmissions (both 4 speed and 5 speed) have been around for several years since the early 2000s so they must be very reliable.
4 - Having test driven a 5 speed manual Corolla XRS, the 2AZ-FE makes healthy torque of 160 ft-lbs so it will have decent get-up-and-go especially compared to the 132 HP 2ZR-FE base model Corolla. Compared to your mom's Camry 2004 LE, the 2AZ-FE XRS weighs only 150 lbs less (2960 lbs for the XRS auto vs 3100 pounds for the Camry LE 2004) so the reduced weight and better gearing with the 5 speed auto (your mom's Camry has 4 speed auto) should help in get up and go feel much better and peppier, but do not expect it to be radically different than the performance of your mom's 2004 Camry.