I only hiked the INT in the Negev. And even there I cherry picked and skipped some not so interesting sections. Hiking the rest of the INT is very, very low on my bucket list after reading
Buck 30's trip reports of the entire INT. He disliked the Northern part of INT and loved the Southern part. All my conclusions and recommendations refer to the Negev section of the INT only!
Did I like this trip? Yes, tremendously! In fact, this is one of my Top ten hikes ever! I have hiked ten thousands of kilometers and I have hardly ever been on a trail where there are so many highlights every single day. When it comes to spectacular landscape this is one of or even the best hike in my entire career. The Negev is simply breathtaking!
But would I recommend this hike to a friend? It really depends on the friend. This is not a hike for everyone and despite all its beauty I can see how this trail can also turn into a nightmare! Why?
First of all this is also most technically difficult trail that I have hiked. You really have to climb at many places and these are not easy climbs. I was very happy to have a hiking partner this time to help me lower and lift our packs and have back up in case of an emergency. You don't have to be an athlete though - even teenage school kids manage to hike the trail. But they are in a group, have no backpack and can help each other. If you want to hike the INT in the Negev alone you should be sure footed, have no fear of heights and be fit. Very few diffult sections are equipped with ladders or cables to help you! Definitely bring trekking poles and try to keep your backpack weight as low as possible. At least navigation is not an issue. The trail is very well marked. You don't need a GPS. A smartphone is enough as a backup for navigation.
But there is the water problem. We have hiked in winter with very low temperatures but also very little daylight. In December 3 to 4 litres per day were more than enough but hike earlier or later and you will be in trouble. Hiking the INT without expensive water caches is more than doable though. Just have a look at
Buck 30's excellent water report that tells you all that you need to know. The only English guidebook of the INT by Jacob Saar is a total failure in this respect: It hardly describes where the water sources or even misses them! The guidebook is only good for its detailed maps - forget about the trail descriptions or good planning advice.
Then there is also the "night camp" issue. Officially you are only allowed to sleep in the official night camps. You are not even allowed anywhere else in the Negev at night. And there are rangers who are controlling it - and fining offenders. These night camps can be totally deserted - or full of more than 100 screaming schook kids. Most of the nights camps we passed were full of school kids... Like Buck 30 we mostly stealth camped using LNT principles. Decide for yourself what you want to do!
Also keep in mind that Israel is not a cheap country. In fact I found only two things to be cheap: bus travel and mobile communication. Buses run everywhere (except on Shabbat!) and you have cell phone coverage even in the desert. But everything else is expensive. You will not to be able to splurge or treat yourself very often. Bring hiking food from your home country if possible. There are a lot of trail angels along the INT though.
The Negev is one of the most impressive and fascinating places I have ever been. Just make sure it is not more than you can take.