7 was just rebranded vista. It was basically vista sp3. MS knew the vista name had been badly tarnished.
The are several reasons why vista churned so badly at startup was the indexing service and the service that was trying to load everything into memory. Turn those 2 off and vista worked as good as 7, I did this to dozens of computers and the owners were so happy. Several other background services needed about 1.5GB of memory just to get the system up and running. This was when 4GB of machine was considered 'huge'. By the time 7 came out they had fixed both of those services and a 'crappy' machine had 4GB. Dumping it on a box that 512MB of memory and it struggled badly (512-1024 was the sweet spot for XP). 8GB for Vista and up and for proper use of that, you need the 64bit ver.
I am currently using Windows 7 in my personal machine (and Linux in others).
The indexing service often gets disabled because it makes the machine slow down a lot.
Also I really miss Linux "swapyness", Windows Vista+ (10 included) are really aggressive in swapping, more than needed, often my machine ended trashing because of Swap while still having 20+ GB free, this is in part because of that stupid indexing and cache, Windows 7 has a habit of giving priority to the cache, putting files from the most accessed programs in the RAM, and not caring if your CURRENT program need RAM...
I use the indexer setup to ignore parts of my system. That works pretty good. Especially if you are doing any work with nodejs. Also defragging just the index file helps a lot. That thing can end up with thousands of bits all over the drive. Even with SSD it is not great as random seek on many SSDs are fairly terrible and contig read is amazing. One trick I also do is pre-allocate my swap file (I usually pin it to 4GB). As the default is to grow/shrink.. That can do the same thing as the indexing file.
Something also changed around sp2 with 7 and file writes. Files get fragmented very quickly now even when there is plenty of space not to do so. I usually would only end up with systems badly fragmented in XP if the drive is full (much like ext4) now it just does it as a matter of course and is acting like the old DOS alg of find the next free spot.
You can still turn off the readyboost/superfetch cache service (not sure where it is win10). If you have an SSD you should not notice much difference on or off but it can happen. Turning those off makes your free RAM act more like in linux where it just caches recently read items and gives it up right away if needed.
When Vista came out I bought a new machine with AMD A6 4600+ and 2GB of RAM with Vista 64bit and it ran great. I had no driver issues or performance issue even with default install. You didn't need 4GB of RAM, you just needed new hardware. Limited RAM and drivers for the older hardware were the biggest problems, Microsoft drastically changed the driver DDK and many hardware venders had poor quality or no drivers which led to many of the problems people had. Kinda sad I got rid of this machine, it would be interesting to benchmark it to a Raspberry PI 4 in Linux.
I'm convinced if they had set a higher minimum system requirements and hid the pre-loaded memory from the task manager or labeled it more clearly Vista would be a lot more fondly remembered. Most of the people I met with negative experiences were running it on walmart "vista ready" computers that should have never certified in the first place or upgrading their old pentium 4 machine with 1GB of ram and expecting a good time.
The are several reasons why vista churned so badly at startup was the indexing service and the service that was trying to load everything into memory. Turn those 2 off and vista worked as good as 7, I did this to dozens of computers and the owners were so happy. Several other background services needed about 1.5GB of memory just to get the system up and running. This was when 4GB of machine was considered 'huge'. By the time 7 came out they had fixed both of those services and a 'crappy' machine had 4GB. Dumping it on a box that 512MB of memory and it struggled badly (512-1024 was the sweet spot for XP). 8GB for Vista and up and for proper use of that, you need the 64bit ver.