Users have full access to literally do anything if you give them access. I usually block them from changing my default reports and instead let them copy and change in case they screw it up. The report designer is what I use to create the report in the first place so the end user also has this tool to make whatever changes they need. However, apart from a small handful of users most only ever use it to move a few fields around on a cheque image to get it to line up with printed laser cheques.
I only used L&L as all my existing reports were already done and it does actually render really nice looking reports and has a bucket load of options to solve any reporting issue I have come across. I'm not sure I would recommend it for someone starting out. Solace who supported it originally is now defunct, I had to do a major hack on the template to get it to do what I wanted and there is a steep learning curve to creating reports in the first place. Russ took over the templates and I think re-wrote them but last I heard I think they are now open source.
My original point was really about the process rather than the tool. What I am attempting to do via SOAP I think you could do with lots of Report Designer tools not just L&L.
Cheers,
Kev