The phrase "arguably slower" is correct and usable in written English.
It can be used when presenting a point of view that suggests something may be slower, but acknowledges that this is open to debate or interpretation.
Example: "The new software is arguably slower than the previous version, depending on the user's system specifications."
Alternatives: "possibly slower" or "potentially slower".
The twig is removed at marriage, and the hole enlarged either by a knife or the bridegroom's penis — an arguably slower and more enduringly painful prelude to penetration.
As a semiconductor technology, LED lighting has a price-performance curve much the way computer chips do, although the rate of improvement is arguably slower.
Nevertheless, we can also find an exception to the rule: The travel speed from Dakar to Ziguinchor is arguably slower than to many other cities that are of same distance from Dakar.
The Democratic policymaking elite have been arguably slow to reflect that consensus.
The pace of new drug discovery and treatment innovation by big pharma companies has arguably slowed, however.
Others bend their results or curtailed their researches to fit the prevailing view, arguably slowing down the process of scientific discovery.
Meanwhile, the arguably slow-to-come digital revolution in its popular image means that OS can preserve the quality of and demand for its paper maps, while going to town with app innovations.
But the unwillingness to take responsibility for Ofsted's failures in the Trojan Horse case plus his forthright language have damaged morale and arguably slowed progress in the cities he criticised.
One reason to focus its efforts on the keyboard was that Apple initially blocked developers from offering system-wide keyboards on iOS, and was also arguably slow to add more advanced features to the native iPhone keyboard leaving a gap for others to exploit.
That accusation is rejected by the government of President Enrique Peña Nieto, which, after an arguably slow start, has deployed massive resources to find the students and their killers.
So far, with the notable exception of the so-called "black protests" against a total ban on abortion, the protests did not reverse the ruling party's actions, although they arguably slowed them down.
