So I thought that it would be fun to right a little on the things I've learned playing my BT. First I'll start with HQ:
The Emperors Champion is a surprising killing machine. When I first looked at his profile I saw the 2 attacks, and gasped in horror. However after playing a few games I realised just how good he is at character killing. All you need to remeber is to always take the vow: Accept any challenge, no matter the odds. I'll get back to how the vow effects the army later, but it gives the emperors champion himself a huge boost. When you get to re-roll hits he will probably hit with those 4 attacks on the charge, and with 2+ to wound against most opponents, he'll wreak some havoc.
The commander hq choice (marshals and castellans) still have the old space marine commander rule giving the rest of the army their leadership. This is very useful for BT, who dont have sergeants to boost ld and have to take tests every freaking time a single brother dies. The chaplain isnt such a boost if the army has selected the vow above, since his re-rolls to hit are already covered by preferred enemy. BT dont have librarians.
A special unit springs to my mind immediately: Assault terminators. With preferred enemy and lightning claws they re-roll everything in closecombat. Top that with furious charge and they are devastating.
A small note should go to the dreads. They are the older model and can be kitted with the old venerable upgrade. When I have the points I give my missile-lascannon dread venerable and tank hunters, to knock some antitank power, but this is expensive.
Well there is only one squad type: crusader squads. The benefits of scouts and marines being in combined squads, is to get some cheaper bodies in there. Also you have the chance of fielding 20-man squads. Crusader squads even get land raider crusaders as dedicated transports, however you should never do this unless if you run out of slots. See dedicated transports cant transport any other unit then the unit it was bought for (the book is full of 4th ed rules like that). Crusaders cant have sergeants, but instead of a heavy weap they may upgrade one model to have a pw or pf. With the PF you should bear in mind that the model will only get 2 attacks on the charge and 1 in latter rounds. Get that preferred enemy!!! Heavy bolters are only 5 points in the crusader squads for a reason. Since the unit always has to move if it is fired at ( and they pass their ld test) you wont be having a very fixed gunline. However since the rule in the codex refers to the rules for consolidation in the rulebook (in which the distance moved is optional), you only have to move 1". This might still pose a problem when trying to hold objectives. I mount my crusader squads into rhinos with pistols and ccws and hope the rhino doesnt blow up, snatching objectives on the last turns by tank shock.
They suffer from the old dedicated transport rule as stated above, but have a huge advantage from cheap extra armour and old smoke launchers. The old smokes almost guarentee the rhino wont be blown up for a turn (unless you opponent is firing everything at it to force enough immobilised and weapon destroyed results).
This sections is similar to that of the 4th ed space marines. I should however point out that assault marines can buy storm shields (old weaker ones ofcourse). The bike squads can buy either 3 special weaps or three power weaps (but no sergeants again).
The laind raider are unfortunately a little dull now that you have the new shining vanilla raiders. Blessed hull can save you sometimes. The main problem with the HS section is that its missing whirlwinds and devastators. Ofcourse the devastators would be impractical with the BT's hot temper, but I really love whirlwinds.
So hear is a small breakdown of the codex (I know I've only scratched the surface, but I tried to bring up my views). Also a list of what I like to field at 1500 points.
Emperors champion (you know the vow already?)
8 assault termies
missile-lascannon ven. dread
4 crusader squads (small 5 man)
(they are jawaballs style snatching units)
2 typhoon speeders
Im thinking of kitting the typhoons with multimeltas to add antitank punch, but I usually keep them back to wait until the last turns and then contesting objectives, so the multi-melta wouldnt fit that role, but some meltaguns to the crusader squads would be a way to go probably.