I have just recently started riding 7 speed after riding 9 speed for over 15 years. I find that 7 has no drawbacks. With the exception, Hyperglide cassettes are very hard to find in anything other than 11-28+.
My old tricolor will not except an 11 and I refuse to concede that I need 28. Try finding a new 12- 23 or 13 -26.