tpvn

For those who travel with kids like us, it is enlightening how our preference has changed. Our trip in December (LAX-SGN, on EVA) has been on my mind recently. Even though this will be our 3 years old 3rd trip to the same destination to visit the grandparents, I feel it is only moderately less stressful compared to the first time. Always feel guilty dragging her so far away from home, so constantly try to figure out ways to make her experience better. The other day my wife brought up Jetkids, and I started doing a little reading on it.
Firstly, does anyone here have any good/bad experience with it (or similar products) and want to chime in? Seem like the reviews I saw online were mostly sponsored, so not sure how much I can trust them. Any airline not allowing you to use it inflight?
Secondly, if you have used these products before, would you even bother with premium economy (more pitch, but immovable armrest) instead of standard economy?