I'm reading a variety of questions in your post.
1) Computer vs. no computer
2) Console computer vs. wrist-worn computer
3) Air-integrated (wrist) computer vs. non-air-integrated (I added this one)
I'm a fairly new diver. I dived with a console computer for my first ten dives or so (rental) and then was given a non-air-integrated wrist computer (lucky me!) when one of my buddies went to an air-integrated one. So I now dive with the computer on my wrist and a hose-mounted SPG at my side. Notes:
1) Although I learned tables, I have always dived with a computer, so I can't compare to not having one.
2) I love having the computer on my wrist. It has especially allowed me to easily practice slow, "even" ascents. In fact, I have wondered if I might be too dependent on it and should practice ascending without looking at it. At any rate, I really like having it there.
3) From observing my buddy's experience with the air-integrated wrist computer (in very random order):
a) It is a LOT more expensive initially
b) You have a smaller selection of computers (especially if buying used) to choose from (although this will probably shift)
c) It is kind of neat
d) You have to be a bit careful of the transmitter that is (often) located near the tank valve
e) I check my air as often as my buddy, it seems, but I did have to develop a motor-memory system for it
f) I think I still prefer the non-air-integrated
g) If you are debating the cost of a computer at all, I can't imagine that you would want to spend the huge amount more for an air-integrated one.
h) I have to write down my pressures for later (dive log), whereas my buddy's come up as part of his computer log that he can download.
i) If the AI computer goes on the fritz and you decide to save the dive by using tables, you will still need a "physical" SPG setup if you want to monitor your air pressure.