Originally Posted by mprince

Got my SIDI's yesterday, definitely a high quality shoe (not a surprise). Definitely more toe room in these compared to my Energy 2's, and overall comfortable (although I can't say they are noticeably more comfortable than the smaller shoe). Unfortunately, even though I followed Merlin's online sizing guidance, I think these are a bit large as I get a bit of heel lift walking around the office that I don't get with the 48's. So since the width of the older 48 is comparable to the new 49, the 49's are going back and I will get a pair of 48's to replace them. Live and learn, that is the danger of buying online (and taking advice from same).

Edit - got a pair of Genius 10's on the way in size 48. Already shipped from Merlin, they may be here by the end of the week. These supposedly have a bit more room in the forefoot than the "traditional" SIDI last (according to more than one online review I read). These are what I really wanted in the first place but could not find them in 49.