Seat extenders for flights with toddler - worth it?

I'd check with the airline first. Many are no longer allowing these types of seat extenders.

We have a JetKids.  My kiddo doesn't love it for sleeping because the height doesn't usually line up with the plane seat and it is hard to keep it locked in place.  But it is great as a kids' carryon (fits under the seat in front for takeoff and landing) and for riding around in the airport if you are not bringing a stroller.

We have this exact product. 

Our first use was in August with our then 20 month old flying from SFO to JFK, approx 5.5 hr flight. She loved pulling the luggage around the airport. Used as a carry-on, it was helpful as it contained her clothes (in a compression bag), toys, and food. She thoroughly enjoyed when we used it as a seat extender for LOUNGING as she had her blanket, iPad, and headphones (we even attached another blanket in the headrest across to the folding table to create her own pod/fort). HOWEVER FOR NAPPING she never could get comfortable  – she was a hair too long to properly have enough space to lay flat. In fact, the only time she slept at all on the flight was for 30min (from pure exhaustion) lying across all three seats with her head on my wife and her feet on me.

We attempted again more recently on our flight to Kauai for New Year's at 24 months (another 5.5 hr flight) and it was the same issue. Further, her feet/legs now push the extender in a way to make unusable.

It's a great product as a piece of luggage, but we've never been successful with the seat extender. Unless you have a VERY CHILL kid who sleeps easily and/or they are on the smaller size, I wouldn't depend on this feature. It probably would have worked for a toddler 18 months and younger. 

I’ve heard great things about the Stokke bedbox, and was planning on purchasing one for our son (we have family in France.) However- I found out that many airlines do not allow them to be used on flights, as they are considered a hazard if there is an emergency. I believe their website has a list of airlines that do allow them to be used, though, so you may want to check if your preferred airline is in there. Good luck! 

I fly to London annually to visit family with my now almost 4y/o. I bought one of these (the Stokke Jetkids) when my son was 2 and had to have his own seat. Hands down one of the best decisions I've made! It really helps him get comfy and sleep when that's what he wants to do, and it's also his own bag he can enjoy packing with entertainment items, AND it's great fun for him to sit on and wheel himself around the airport (and when needed i can take the straps and pull him around). I highly recommend it.

VERY happy with my jetkids bedbox purchase. Some actual sleeping on it at age 3. Kid needs to be in window seat (or center of center row) for it to be allowed for safety reasons. We never call attention to it; checked that the airline we flew on allowed it the first time but haven't bothered since, and so far no issues on 4 different airlines.

Better luck with the sleeping on a night flight where they actually dimmed the cabin lights. By age 3.5, kid more interested in sleeping laying on us. But still super happy with it as luggage that kid at 3 would love to ride on and actually stay put on as we pulled it, and not run around the airport, so we didn't need a stroller, and now LOVES to pull it "by self!" through airport. It holds quite a bit, very sturdy, and the wheels roll really well; high quality luggage though I'd never have spent that much just for a kid's carry-on. It has also been used with the kid sitting on it and propelling with legs in the airport, basically using it as a kiddy-car, and also did that at an air bnb we unexpectedly found ourselves in with few toys and us parents sick with flu, kid was loving doing laps around the kitchen island. So even if there had never been sleeping I still think we'd have gotten our money's worth. But that first flight where I was so anxious about what kid would be like if there wasn't a wink of sleep and keeping track of kid in airport -- got money's worth in that trip alone.

We sprung for a JetKids suitcase for a trip to Asia. He didn't sleep for the whole 12 hour flight, but it seemed like it was more comfortable for him to have something to rest his legs on than having them dangle over the seat. Took Korean Air, no one said anything on the way there, but a flight attendant made us put it away on the ride back. We relied on Stokke's customer agents assuring us that it was the flight crew's discretion but turns out there was an official policy against it. That said, our 4 year old had an absolute blast riding on it through the endless airport hallways, sitting on it when the immigration line got boring, and people seemed delighted to see him riding on it wherever we went. Not sure it's worth the price but we were glad we had it!