The primary activity of RppH is to remove pyrophosphates from the 5’ end of triphosphate RNA. However, RppH does have decapping activity as well and will leave a 5' monophosphate when incubated with capped RNA. Here is a link to the protocol for this application. https://www.neb.com/protocols/2015/01/14/decapping-eukaryotic-mrna-with-rpph-neb-m0356. There is a reference at the bottom of the protocol that highlights the decapping activity of RppH.
Although we have not done a direct comparison between RppH and TAP in-house we have received significant positive feedback from customers using the enzyme in place of TAP. Note that customers using the decapping protocol will need to purchase the 10X Thermopol Buffer (NEB#B9004) separately. The enzyme is sold with NEBuffer 2 which is ideal for its pyrophosphate removal activity.
Hetzel J, Duttke SH, Benner C, Chory J. Nascent RNA sequencing reveals distinct features in plant transcription. Proceedings of the National Academy of Sciences. 2016;113:12316–21.
Neri F, Rapelli S, Krepelova A, Incarnato D, Parlato C, Basile G, et al. Intragenic DNA methylation prevents spurious transcription initiation. Nature. 2017;543:72–7.