Your view
My own view is that …
a number of reservations
One cause for concern is …
It is not necessarily the case that …
It does not necessarily follow that …
… begs the question …
One may question whether …
To claim here that …
… would be denying the fact that …
X claims, in my view wrongly, that …
the question is rather …
it is more likely that …
The point is surely rather that …
One could in fact also state that …
it would be more accurate to say that …
a more promising approach would be …
a more plausible explanation would be that …
It is important to make a distinction between …
It is important to distinguish between … and …
If the most important etc. factor had been …, then it would be expected that …
The author has clearly not understood …
The authors merely pay lip service to …
The paper offers little in the way of …
The paper offers little that is new.
The study offers only cursory examination of …
we should beware of throwing out the baby with the bathwater
While acknowledging the author’s contribution, …
While a valuable contribution in many respects, …
At the risk of offending …,
pace X
… must be examined more closely
… cannot be accepted as it stands
more needs to be said about …
However, given these reservations, …
Despite these reservations, …
Despite these limitations, …
Given these qualifications, …