When comparing PuTTY vs Xshell, the Slant community recommends PuTTY for most people. In the question“What are the best terminal emulators for Windows?” PuTTY is ranked 6th while Xshell is ranked 9th.
Ranked in these QuestionsQuestion Ranking
Pro De facto standard client for SSH, Telnet and Rlogin
Pro Source code available
Full source available. Compile and modify it yourself.
Pro Connections management
Pro Has tabs
Pro Tunneling bar
Channel monitoring and dynamic port forwarding.
Pro Can use any system font
Pro Compose bar to send a string to multiple servers at once
Pro User defined key map support
Pro Local shell interface to control Xshell
Pro Task automation with VB script
Con Tedious logging/tracing
Its tedious to set up logging and tracing (e.g. for serial connections).
Con Lacks features
It is JUST an SSH client. There are many other options with built in X-servers, Multitabbing etc.
Con Can not save passwords
Anyway, you can use "PuTTYgen" to generate a key pair, then use "Pageant" to do a password-less SSH remote login.
Con No global settings
If you want to change a setting for all your connections, you'd have to do it individually.
Con No login scripting
Con Not free
The subscription costs $89 per year.