COMPUTRAINER QUESTIONS

Most likely a pre-mature thread as I haven't even explored this fully so sorry about that - but I'm curious and can't wait to for next week to get an answer...

I just found an enduro fitness club near me that caters to triathletes - endless pool, weights, tri coaches and... a computrainer studio!  I'm thinking it would be ideal for winter maintenance as it gets pretty dark and snowy here. 

I've never used a computrainer but am familiar with the idea that you plug it in and it's as though you are riding the same course as say IMLP.  The woman was describing classes where a group will meet and race the same course together/against one another.  She says the competitive nature of it is stimulating (especially given that it's winter) as well it's a good way to improve your riding. 

My question is - what if you aren't at the same skill level as the other riders in the group?  I can't imagine how this works...  you have the big screen with the program and a group of riders all riding/racing together - It's not like a spinning class where I can just go at my own resistance is it?  One of the courses they train with is the HIM Muskoka course and I *know* I'd never make it on my first attempt.  So unless I ride a course for my skill level - I'm not sure how I could participate in these classes?  Can someone please help me understand the concept?  Benefits? Limitations?

Thanks in advance!