Quality of Bottles Down Down Down

I have three children - aged 14, 8 & 2 years. I bottle fed all three children and used Playtex bottles for each of them. Because of the age difference, I've used different models of the bottle with each child. I was very pleased with my experience with my older two children; however, the new bottles that Playtex uses (that adjust/bend as needed) leak all of the time! In total I've used approximately 20 bottles both 4 & 8 oz size and all of them leak if tilted sideways with caps on! It's incredibly frustrating having to pack bottles in a diaper bag only to open the bag up and find leaked formula/milk all over because they were not kept upright. Because this is my final child and we invested so much in bottles and nipples, we will stick with the product until we are completely done with bottles. However, if I had known that I would have problems like this before hand, I would have opted for a different brand of bottle. The design needs a change!