<p>While the 55-250mm IS STM zoom is not bad at all, the Tamron is the superior lens as Bob already stated!<br />Both zooms have a non-rotationg front.<br>
The 55-250mm is however smaller & lighter if this is of any concern. <br />I use it on EOS M and sold the Tamron because size and weight were not suitable for this small body and the AF was too slow on EOS M. <br />I have had no concerns while I was using the Tamron on DSLR body before.</p>