Hi,
I'm not the very experienced person you're looking for, but I do remember doing my PPL training in a C152 quite well.
Although being a quite pedantic person, I was more than once quite happy about the C150/C152s benign behaviour, especially in the solo part.
I've never flown the 38, but it has a reputation as a plane with a quite contrary philosophy in terms of training. The C152 will forgive mostly everything you do with it, you'll have a hard time destroying it: Its stall behaviour is boring at best, you'll have to abuse it with more than one "mistake" to let it spin and it will leave the spin with the proven Chuck Yeager method: Get your hands off and wait.
The 38 on the other hand will teach you to fly more precisely and it will provide some training in switching tanks.
Personally, I would go with the 152. I'm a confessing coward, so the more forgiving airplane is always my friend :-)
This does not mean that I think of the 38 as a dangerous airplane, it had some issues at the beginning of its production, but I have read some very good reviews about it in the past, too.
Kind regards,
Peter
PS: I don't want to start a war on low wing vs. high wing - I think it's more a thing about personal preference than a thing decidable by facts.