That topic is basically completely pointless. 35 base HP goes a LONG way to making something bulkier, and those "defense tiers" honestly mean nothing.
Ok, so now I know the guy who did that topic was an idiot, and that I shouldn't trust the pinned D/P Information / Resources thread. Thanks for the heads up.
Not to mention that Honchkrow is immune to Spikes and Toxic Spikes, and with the way UU is shaping up, Spikes are infinitely better AND far more common than SR.
Spikes and T-spikes, far more common than even the infamous Stealth Rock? I'm not sure about that. Can't find anything showing the most commonly used moves in May, so I'll just look at it like this:
Spikes appears on exactly 4 Pokemon with 1% or more usage during May:
Cloyster (4.4% usage, Spikes used on 83.1% of them; so the usage of Cloyster that carried Spikes was 3.6564%)
Omastar (6.3% usage, Spikes used on 46.4% of them; 2.9232% overall usage of Omastar carrying Spikes)
Qwilfish (2.9% usage, Spikes used on 10.2% of them, 0.2958% overall usage)
Roserade (14.5% overall usage, Spikes used on 44.2% of them, 6.409% overall usage)
Adding those percentages together, you get 13.2844% total usage of Spikes across all UU Pokemon used in May. Add an insignificant amount for other really random crap like Pineco, which was used 27 times and carried Spikes 29.6% of the time, if you want.
Toxic Spikes, used on :
Cloyster (4.4% usage, 34.8% w/ T-spikes, 1.5312% overall usage)
Drapion (5.9% usage, 33.2% w/ T-spikes, 1.9588% overall usage)
Nidoking (3.3% usage, 7.5% w/ T-spikes, 0.2475% overall usage)
Nidoqueen (4.0% usage, 57.6% w/ T-spikes, 2.304% overall usage)
Omastar (6.3% usage, 7% w/ T-spikes, 0.441% overall usage)
Roserade (14.5% usage, 28.4% w/ T-spikes, 4.118% overall usage)
Venomoth (exactly 1% usage, 25% w/ T-spikes, 0.25% overall usage)
Adding up all the percents for T-spikes, we get 10.8505% total usage of T-spikes across all UU Pokemon in May. Adding this to the total usage for Spikes, we get 24.1349% combined total usage for the two moves.
Now, we look at how often Stealth Rock appears, once again listing Pokemon that use Stealth Rock with 1% or more usage (as you might expect, this list is way bigger than the previous two, so feel free to skip it and read the total after it):
Aggron (1.1% usage, 34.5% with SR, 0.3795% overall)
Armaldo (1.5% usage, 45.3% with SR, 0.6795% overall)
Bastiodon (1.0% usage, 77.9% with SR, 0.779% overall)
Bibarel (1.5% usage, 6.6% with SR, 0.099% overall)
Camerupt (1.7% usage, 48.7% with SR, 0.8279% overall)
Chansey (8.4% usage, 33.9% with SR, 2.8476% overall)
Claydol (10.3% usage, 72.6% with SR, 7.4778% overall)
Cradily (1.8% usage, 18.5% with SR, 0.333% overall)
Hippototas (2.7% usage, 95.5% with SR, 2.5785% overall)
Kabutops (6.8% usage, 11.5% with SR, 0.782% overall)
Kecleon (1.1% usage, 71.8% with SR, 0.7898% overall)
Marowak (2.2% usage, 6.5% with SR, 0.143% overall)
Mesprit (3.3% usage, 43.6% with SR, 1.4388% overall)
Miltank (5.6% usage, 41.6% with SR, 2.3296% overall)
Nidoking (3.3% usage, 14.3% with SR, 0.4719% overall)
Nidoqueen (4.0% usage, 63.0% with SR, 2.52% overall)
Omastar (6.3% usage, 23.0% with SR, 1.449% overall)
Pinsir (2.2% usage, 10.6% with SR, 0.2332% overall)
Probopass (1.5% usage, 56.6% with SR, 0.849% overall)
Regirock (9.7% usage, 83.2% with SR, 8.0704% overall)
Registeel (15.8% usage, 74.3% with SR, 11.7394% overall)
Relicanth (2.3% usage, 27.7% with SR, 0.6371% overall)
Rhydon (2.5% usage, 36.7% with SR, 0.9175% overall)
Sandslash (2.1% usage, 53.0% with SR, 1.113% overall)
Shuckle (3.0% usage, 38.5% with SR, 1.155% overall)
Steelix (11.5% usage, 83.5% with SR, 9.6025% overall)
Torkoal (1.2% usage, 34.9% with SR, 0.4188% overall)
Torterra (2.9% usage, 22.4% with SR, 0.6496% overall)
Uxie (9.4% usage, 82.7% with SR, 7.7738% overall)
All of that adds up to 69.0852% total, overall usage of Stealth Rock across the movesets of all significant UU Pokemon, a figure over twice as large as the totals for Spikes and T-spikes combined. So, as far as the most common entry hazard in UU goes, I'm gonna stick with Stealth Rock, and say that if I have to choose between not being SR weak or being Spikes immune, I'm gonna go with the former.