If you can afford it, go for it. Because it is a bustling green campus with 40 odd colleges, you will have an unforgettable experience. Placements used to be nice, but they’ve taken a hit recently; however, they’re still good if you’re good at studies (scoring 6.5 CGPA).
LD is also a good college, but it’s not better than BVM, aside from the affordable fees and the fact that it’s in Ahmedabad.
You should also know that LD College and BVM are Engineering colleges. Whereas, Sardar Patel University V.V. Nagar provides B.Sc., M.Sc., and other non-engineering courses.
Now, here’s a comparison of BVM and LD that will give you get a better picture.
Overall, I would recommend BVM.