I think it’s tacky. But to tell the truth, even if you get glassware, it starts out all nice and formal and by the end of the evening people are swigging bottles. Just ask your photographer NOT to take photos of anyone dancing with a bottle in their hand.
Because you raised the question, I think you are feeling a little uneasy about the bottles. Is it because you think the plastic looks like airline ware? Or you don’t like plastic? Is the venue inside or out? If in, rent glassware. If out, you may go with the plastic cups. Make sure they are tall enough and wholesale clubs like Costco or BJ’s may or may not have the height you want. Last year at Easter time, Costco did sell colored plastic drinking cups, and it was so cute. Or go online and look for cups that match your color scheme. They don’t have to be clear. But, should you go clear, that’s classy looking in a rustic sense for an outdoor wedding. Just whatever you do, make sure the height is tall enough for the entire bottle.
A friend did glasses at her outdoor wedding and the bartender said, “Please bring your glass back if you want a beer refill.” That cut down on a major expense of having people leave their glasses hither and yon and having the wait staff pick up all night long; and cut down considierably on the rental cost of glassware. If all things are equal, I’d go w/asking them to return their glass all things being equal.
Skip the signature drink, stick to what people like and know. The concept is nice; but, you can’t guarantee people will like it and you don’t want them taking a sip and leaving their full glass at the nearest depository table. Beer drinkers will drink more per hour than hard liquor generally, so keep that in mind if renting glassware.
You and he know your friends, so size up how many of what you think they may drink. Ball park the others based on the ages and what your parents generation will drink.
Go to a store that accepts returns. Keep it to one red and the whites which are really popular. Somehow red seems heavy. I know that people often ask, “Do you have abc, and the bartender says, “we have def,’ and the person says, “Oh, that’s OK.” So don’t stress. If it’s free, they will always find something they like, don’t worry.
Enjoy your day. In the long run, these are minor details that no one is going to remember one way or the other. But, they will remember if you don;t send a thank you note, if you are not happy and smiling that day being welcoming and courteous to your guests. If there is something which will stress you out, then even if it costs a little more to do it another way, do it. In the long run what’s a hundred or two either way? Only you know your heart and from the place you asked this question. Be happy.