i know what you mean by "nutrients are nutrients" and on paper, that seems logical, but i have always make better gains when i'm eating more real food and it seems to hold true for the majority of people i've worked with. i use shakes at a couple of specific times of the day. first thing in the AM, post workout and right before bed. this changes during contest prep, but for most of the year, these are the times i use shakes. whey is in your system quickly, so it works well when you first wake up and right after training but as dr scott conley has said, it is also out of your system quicker than whole food protein sources. he belives that you have about an hour window with whey. it's good for getting anabolic, but you want to quickly follow it up with solid food. 30 min after my moring shake, i'm eating. 45 min after my post training shake, i'm eating.
i understand that logistics may make your work hours less than ideal for getting your meals in, but maybe you can find some middle ground. i work with a lot of guys who are in your situation, not able to use a fridge or microwave. the key is taking the time to prepare food ahead of time. get yourself a portable cooler. its the working bodybuilders best friend. there are options, especially in the off season, that are quick and easy. if you eat bread in your diet, you could make chicken breast sandwiches, which are easy to eat on the go. if i had to, i'd sit in the bathroom while i stuffed my face for 5 minutes haha. almonds are a good 'on the go' fat. you can put a bag of them in your pocket and eat them after your sandwich break. even if you were to start by replacing one of your shakes with solid food, you may notice some imporvements in your gains over time. so in an 8 hour day, you may need 3 meals. you could do a larger lunch that can be eaten cold for your lunch break, say tuna or chicken with a carb, a sandwich for the afternoon or morning and then a shake for the other meal. add in some peanut butter and oats and ur shake will be a decent meal replacement. i preblend shakes like this, then throw them in a shaker cup, and pack it into my cooler.