Laptop vs Desktop for ML/AI work under $1500

I’m trying to decide between getting a laptop vs. a desktop for ML/AI work (mostly small to medium models, and app development). My budget is around $1500, and I’d really appreciate some input because I'm a bit confused right now.

I’d prefer a laptop for portability, but I’m open to a desktop if it's cheaper and the performance difference is substantial. I'm planning to use it for Python, PyTorch/TensorFlow, and general dev work.

Few laptops I've shortlisted:

• HP Victus 15 (i5-12450H, RTX 4050)
• ASUS TUF series
• HP OMEN Transcend 14
• Acer Nitro V 14 / Nitro V 14 AI
• Acer Nitro 14 (RTX 4060)
• Acer Nitro V 15 (RTX 4050)
• Lenovo LOQ 15 (RTX 4050)
• MSI Sword 15 White (RTX 4050)

I'm trying to find out-

• Is it smarter to go for a desktop at this price for better GPU performance?
• Among these laptops, which ones have better thermals and long-term reliability?
• Is RTX 4050 enough, or should I push for RTX 4060 within this budget?
• Any strong opinions on build quality or hidden issues with these models?

If you’ve used any of these (or similar), I’d like to hear your experience, especially for ML workloads. Or if you think any other model would be a better fit for my requirements, please let me know.

Thanks in advance!