Although it seems the lack of synch from device to computer is what Apple have designed, it is frustrating for those of us with higher capacity devices who don't have a problem over the size of the app. I do not use the cloud, I usually download to my iPhone 6plus as whether on wi fi or using data, it downloads apps pretty fast. My computer downloads apps extremely slowly (but not music or films). A 5GB film downloads in just over an hour usually, yet a 20 Mb app can take up to 40 minutes - but on my phone it takes one minute if that. I then would sync to computer and then at some point sync my other Apple devices with iTunes and all up to date.
At present there's masses of app updates, some apps are updating twice a day as well. I'm on unlimited broadband but get throttled if I use a lot of data a day and in the past couple of weeks that has happened a lot due to the amount of updates and my purchase of some films.
I also have some apps that are no longer in the app store, these are all held on my computer and backed up elsewhere and my advice is that any app you find useful could disappear from the app store so it is worth having a back up.
I don't need to save space on any device or my computer (128 Gb devices and a 2 Tb hard drive on computer).
I am about to acquire the 6s plus and really hope that will not, as has been suggested by someone on here, need all the apps re-downloading direct to the phone as I suspect that having got all my apps up to date on my computer, they should transfer to the phone when I use the restore from my existing iphone 6plus back up. I have 21.33 Gb of apps on my iPhone and I doubt my broadband provider would like me to download that amount of data in one session.
It was a nice idea of Apple's to help those with 16Gb devices to store more on their phones but might have been worth their doing some research as to how people deal with apps. As one user on here said, woe betide your finding you have to restore your phone in an emergency without an internet connection if the apps do have to be re-downloaded from the cloud rather than from computer.
For the time being I will have to download all apps to computer and transfer to device, I was away for a few days during which time 53 apps needed updates, I could have downloaded them to my phone as I have a mi fi mobile broadband device and sufficient data but there seemed little point doing that as I would still have to download to PC for my other devices. So rather than downloading one or two apps as they appeared when I got home last night I had 53 apps to download, all downloading slowly, and slowing down my computer almost to the point of it being unusable.
Note that when you transfer the updated apps to your devices, looks like the iPhone works out that the app has updated and removes it from the update list, but my iPad and iPod Touch still show the app in the update list, but the update button changes to 'open' and after a few days they disappear from the list.