The product lines have evolved over the years and the rating would really vary from product to product rather than the whole range (that offers some great things and at the same time some mediocre stuff).
Formula 1 doesn't offer much to the table, with their shampoo mostly being seen everywhere which there are so many copies of that its hard to find the real one.. It can however be a good starting point when you've developed the fact in your mind that car should be washed with a shampoo and not detergent.
Turtle is from the early days of car care industry and something that consumer oriented and available off the shelf. Their hardshell (green box) wax has been very famous among typical consumers and still is. Their platinum series is good too and their new ICE range is their latest that does offer good products given its price bracket.
Bother Mothers and Meguiars are a level up offering both consumer ranges and professional ranges (mothers being in between turtle and Meguiars). Meguiars however is a very diverse company thats driven car care with its innovative ideas/products that others have followed. Being very affordable, They offer some great products that suffice to take extremely good care of your car. Their pro range typically offered in gallons is extremely value for money and is possibly the most used internationally by detailers.
Sonax is a german brand and the products you see available locally are their lowest most consumer oriented tier. I have some of their high end range products (PNS, BSD) that are top notch and unmatched by other ranges. Their compounds/polishes (not available locally) are considered top rated by many pros and competitive to the Menzerna range (which is considered the best there is in polishes/compounds and comes from Germany).
Chemical guys is a similar brand that is very marketing hyped 
CG stuff is mostly relabelled too (mainly SmartWax range and then selective products from others). Read their product descriptions and you'd feel you've found the holy grail :). But then again some of their products are top notch, while others are so so and some meh... CG offers very redundant products too that do exactly the same thing as few others in their range. But some of their products are really liked by many.
Online reviews for some of the famous products are very helpful when you go through them over a wide range of sites done by trustworthy detailers.. But then, as with everything, TO EACH HIS OWN... As Mike Phillips says, "Find something you like and use it often"
I hope this helps..
