The negative effect of this change is perhaps that it reduces some of the 'edgeplay' and tension of "I just got enough for that finishing degree".
The positive is that it may reduce one of the game's perhaps major slowdowns: calculating DoS.
As those 'edgeplay' cases were reasonably rare, the impact of the change is likely overall positive-- and of course, GMs who like a bit more calculation can always award successes for closeness.
However, a full d10 system, where there is almost no edge for basic success and perhaps no ability to use +5 alterations would likely be quite dull.
Percentile d100 does have significant advantages as a base over d10, including perhaps the often overlooked 'familiarity' effects.