OK, I had to add a few thoughts. First, regarding stage 3 foods, I believe they are TERRIBLE. Both my kids (ages 9mo and 3 1/2) have been able to eat almost every variety of table foods and they gag/choke on stage 3 foods. They are actually more confusing then helpful to alot of babies because the texture is so mixed. The initial reaction because of the smoothness from the puree part is to simply swallow, and then suddenly they hit a chunky spot and gag. Table foods, such as jarred veggies (carrots, peas, green beans, etc.) are soft and easy to mush/gum down, but the solids consistency is not confusing. By the way, I'm a pediatric physical therapist, and my speech therapist co-workers who work on feeding with kids who have feeding difficulties have found the same thing- many kids do not do well with stage 3 and do fine with real solid foods. So, I would say try real table foods that are soft and see what he does, if he can't handle it, then go back to your pureed foods and keep trying periodically. On a side note, my pediatrician is very conservative and he has good research to base his decisions on (for example, he does not recommend any food other than formula/breastmilk and maybe rice cereal until 6 months), but he does not really recommed baby foods at all because they taste different and once they get older, transitioning from baby to table foods in the toddler ages is like introducing a new food entirely and they often reject it, while babies are very open to trying new foods.
I know that everyone has a different opinion, but based on my doctor's recommendations, once they are 6mo. of age, if they are taking 3 good meals a day of table foods with a good and healthy variety of foods, he does not worry at all about the nutritional value or need of pushing the bottle. So you can do your own research on this, but I wouldn't worry about the bottle at all.