Apart from the drilled hole - my view exactly.
And with all the pro's for polyurethane as compared to rubber based elastomers
I personally would never go another route as long as a poly version is to be had.
Poly is:
usually much easier to fit
by virtue of its chemistry impervious to ozone, petrol, grease and oil(s)
usually fitted with a stainless insert tube
usually nicely coloured (which is a bonus when looking at the finally finished restoration you've accomplished)
usually more costly
Rubber is:
none of the above, especially that last line.
(But if it gets soaked in oil or petrol or ozone - or time - it will need to be prematurely changed out,
long before the polyurethane version would.) YMMV of course. [:D]
I know lots of people who prefer rubber "because that's what British Leyland, or whatever, specified"...
<font color="red"><b>My two 1980 Wedges...</b></font id="red">