I was running a Murnan Red Dot EVO2 with the Sirio 2611 and it runs good but beware if using on a short track. For my track the top end comes in too late. On a long straight the 2611 pulls hard.
Mr. Murnan was kind enough to lend me an IDM 2617 and it rips from mid to top. Bottom is still good but i think the Sirio bottom is better. Top end comes on a lot sooner with the 2617 and it keeps pulling.
2630 on my Red dot choked the top end but again the bottom and mid was killer.
Haven't tried a Picco 2607 yet and I haven't tried my MF 2602 yet.