rails3 finders, rails3 gure's and MVC police

I've been experimenting with rails since before 1.0. I actually deployed an application with 2.0.x something. It is my test application that has been written in Excel, Applescript, PHP, Active4D and Rails. It is just a little local golf group scoring application - AKA sort of a handicap system.

With each language I've enhanced the system but I choose to start from scratch with Rails3. (I could not get the rails upgrade plugin to work - but I needed to de-PHP the application anyhow). I overwrote the generations and the CRUD part of the application are pure rails3. There are some complicated scoring algorithms that are part javascript and part framework code. I was trying to clean up that part and have made some observations.

Simple models    group has many members # Enhanced to handle different groups       member has many rounds # where the scores are stored

There are other things like course, tees, events etc that come into play in this post

When scores are entered (for each member at the event), it goes through a multi form process. The first part determines who played in this event. The second part verifies the input and saves the data.

In the verify view I query the rounds played for the member on the course and each course tee and compute a "quota" or handicap for that course/tee. In rails 2.x I had something like:

     cond = 'member_id = ' + member.id.to_s + ' and tee_id = ' + tee.to_s      ...     therounds = Round.find(:all,:conditions => cond, :order => "date DESC", :limit => group.quota_limit+1)

The MVP police question is "Is this okay? I not, what rule does this break? and how would you do it?"

Playing with rails3 finders, I came up with something like

    therounds = member.rounds.where(:tee_id => tee).order("date DESC").limit((group.quota_limit + 1))

Rails3 takes almost twice as long ( 700ms vs 1300ms). Is this going to be improved?

I really like the rails3 approach, but is it going to be twice as slow?

Steve Alex