Hilleberg have a great reputation but there have been a fair reports of problems with their zippers in the last few years.
Thing that would put me off is the 4kg, absolutely no way you'd find me lugging a 4kg tent around but then i'm more a hiker than a camper so it really depends what you intend to do.
If you're not hiking far with it then i'd go for something bigger as weight wouldn't be that much of a worry, if you're likely to be hiking though i'd look at something like the
Tarptent Stratoshpire 2
Mine comes in at around 1.3kg, is roomy even with 2 fully grown blokes, has 2 pretty large porches so no climbing over each over for late night trips to the bathroom.
Only down side i've found is a problem with all silnylon shelters, if it's raining the fabric stretches slightly so a tug to re-tighten the guylines is advised.
Even though it's only 1.3kg i still think this is a bit heavy so bought a
Zpacks Duplex earlier in the year.
Still a roomy 2 person shelter (slightly narrower than the SS2 but more room lengthwise), still has 2 roomy porches, still has mossy netting, but it's a single skin tent.
We did manage to tear a corner on a recent trip, but to be honest we were in 60mph to 90mph winds so there is not much this side of a house that'll stand that sort of beating, for a less than 700g tent it's a testament to the quality of the tent and fabric that it stood all through the night.
It's really down to what you want to do.
A bomber of a tent sounds great sat at home, if you're covering any mileage of ascent though it makes less and less sense the further you go.
4kg is a fair bit of weigh to be lugging any distance, you then have your sleeping bag, rucksack, sleeping mat, stove, food, clothing, if your son is young you'll also likely be carrying his kit as well.
I weigh all my kit and put it on a excel file, it's amazing how quickly the weight adds up.
For me personally anything over 12kg and i really start to suffer on the 3rd day, if i can keep the weight below 12kg i find i enjoy the trip a LOT more.
Plus it's not like heavy tents like Hilleberg's don't fail, a search will bring the zipper problem but i've also read/heard of broken poles.
The tent might be able to stand a 60mph wind BUT if a peg comes out all bets are off.
Since my Duplex tore i've spent hours searching, reading and asking for bomb proof tents, the conclusion i came to was there is no such thing.
If the wind is THAT strong a bivvy bag is a better place to be than any tent, a B&B better still.
