Ok, so a bit of background: I'm Spanish but live in the UK with my also Spanish partner. We just got married and celebrated a wedding with our family, and are expecting our first child, so I am 22 weeks pregnant.
In my nuclear family, we have always returned or exchanged gifts when unsuitable. I have exchanged items of clothing and jewellery from my mom a few times, and so has she. I won't say this wasn't upsetting at times, which is why in the last few years my parents have decided to note when I'm talking about a want/need and give me money towards that item (e.g. a new winter coat, a keyboard, a ukulele). I have then started a search for the right item for me and used that money towards that item. To us it counts as a gift from them even if I was the one to choose the right ukulele and go to the store. I personally think that's what makes the most sense, and I'm happy I got to select those items.
Now, my siblings-in-law have very kindly gifted us a cooking robot and gifted the actual object to us during the wedding. This means that we have to take it with us to the UK, either as part of our luggage or send it by post. This means extra risk for the machine, and an extra hassle, plus paying for customs and having to go pick up the item when back in the UK. To top this off, the machine is by a Spanish make, which means that any issues with it or broken parts will be much harder to fix as they don't sell it in the UK so they don't have retailers.
Another pet peeve of mine is that this is something I was planning on buying myself at some point, and I'd probably have purchased a better quality item (more expensive, because we are lucky we can afford it) that will hopefully last us longer and have fewer issues, it's the same reason we have invested in a Dyson vacuum cleaner rather than a cheaper alternative. I know these machines are prone to technical problems as they have a lot of parts and there's a lot that can go wrong with them, and I've read reviews on our particular machine and it does seems like we'll have issues with it.
My in-laws think it's rude of me to suggest we return the item and use the money towards another machine that's either from an international make or a UK make for easier access to a technician. They also think that if something breaks we can just throw it away, but that it's ungrateful to return it even when it's adding so many problems (transportation, lack of technical support).
My parents, on the other hand, think like me and agree that while the intention behind the gift is clearly good, the execution has not been thought through.
I have already apologised to the gifters in case their feelings have been hurt, and we will be taking the machine with us as luggage (my husband's decision, not mine). If something breaks, apparently we'll just throw it out. I'd like to hear what other people think of this situation though, as it seems the usual thing to do with unsuitable gifts is to accept them politely and move on, which to me sounds incredibly wasteful on all accounts!