buy one... never look back, great for niggly rust repair clean outs and stuff

used a cheaper model a while back, recently was given a super dooper one with digital speed control and stuff, seems awesome but still waiting for a good job to use it on lol

even the cheaper one was great, only issue is they can chew through the bits and they arnt cheap, so if a small angle grinder or air tool can do the job its better to use that

the flexible extension drive seems like it will be worthwhile, but again waiting for an excuse to use it