Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Two thumbs down to Philips Avent (and Amazon.com)

This is my second review concerning these lousy bottles (my first has been inexpicably 'removed' by Amazon.com). So, for the sake of brevity, I will keep it short: These bottles are not worth your money. Having years of experience working in the production/manufacturing industry and on similar packaging/storage containers, I can safely say that the fault with the serious leak issue lies with the design, production and/or quality control (at manufacturer level of course).Simply put, the bottle's threads (and possibly it's seal where the nipple is seated) need to be re-engineered. Spend your hard-earned cash elsewhere, folks...these aren't worth the frustration or the money.