An investment note from Canaccord Genuity lead analyst T. Michael Walkley on Monday suggested that some of the halo devices for Android and BlackBerry were struggling to get sales even as Apple was succeeding. The iPhone and iPad were still selling very well at AT&T and Verizon in April and, in many cases, were outselling flagship Android devices. The iPhone 4 was the best-selling smartphone at both carriers, and the $49 iPhone 3GS was outselling both the HTC Inspire 4G and Motorola Atrix, according to checks at several stores.