First off happy 4th of July to us Americans (sorry brits) and if you are in the US, enjoy your 4th weekend and have a good time. If you aren't still have a good time, its another weekend! Me I am just hanging out with the wife and eating food, painting, drinking, and waiting for it to get dark enough to blow shit up. To transition back into 40K, having spent today thinking more about the IG after yesterdays game and the last few in general, I am growing to appreciate 7th and the IG codex more and more.
Personally I am a tinkerer, so I rarely stick to a list for very long and I guess as a product of playing for so long, I don't really follow what is considered to be conventional wisdom. I am stubborn so I'll play my army how I like it thank you very much and yes I will win with it too :p. In this vein, I would encourage you all to play around with things, try units that others have said are no good and see how they work. I know I personally poo pooed the retard ogres when the new IG codex has dropped, but having played some time with them and with 7th changing the game, I have softened a little.
Its hard to get out of your comfort zone sometimes, as when you have something that works, its hard to stray from it and try new things. In my book though there are no auto include units. Yes the Wyvern is amazing and there really is nothing to compare it too for what it does at its cost. And if you are looking for that type of firepower, there is no reason not to take it. At the same time, you are not going to lose if you don't take one either. The IG were successful before it came along and you'll do fine without it if thats what you want to do.
In the example of bullgryns, they don't really suck. Are they expensive and have limited options to use? Yes. They are a bit high, especially since you really can't take them effectively in transports and this hurts ogryns more so. That being said, they can work well when used right and with them supporting your army correctly. The same goes for hydras, are they worse than before? Yes. Do they still kill flyers? Yes. Again with 7th, they are a bit better in that quad guns or anything with skyfire/interceptor no longer shooting at ground targets with full BS. They score, have longer range than a quad gun, and can move. This doesn't make them great, but they are a cheap option to deal with anti air especially if you aren't already bringing an aegis.
Psykers overall are ok, the psychic phase of 7th is underwhelming in a good way, psychic powerhouse armies are worse off now than before 7th. Primaris psykers are still good, but really need to be ML2 before they start to be really effective and still are not going to be rocking the game. Wyrdvanes are still usable, though there role now is going to be more effective with witch fires and maybe a WC1 buffing power. They have a place, but are not going to be a mandatory unit.
As I play with more units I like how flexible the IG are, all of the sections are good with usable units, some are amazing and some are ok, but there really are few that are downright too bad to bring. So play with your stuff and build your army how you like it, the codex is good and you can get a lot of mileage out of most units as long as they are used right.
Thats really it for today, back to food and drink and enjoy your weekend!
GG