I prefer LLC's though the protections in law are similar for both LPs and LLC's. The main disadvantage of the LP is that there must be a general partner that controls the entity and this general partner can be attached (sued) and control of the LP can be lost this way. To limit this risk most AP attorneys will reccomend that another entity, LLC, Trust, offshore purpose trust, etc. be the general partner and that the general partner exists soley to run the LP, that is, the GP does not engage in any other business to limit it's risk of suit.
LLC's are descended from LP's and the main advantage is that they have not general partner to attack. LLC members may be attacked but this is difficult in most states and particularly difficult in NV, WY and DE. Can LLC veil's be pierced? Yes in most states, though with varying degree's of difficulty. NV prohibits piercing the veil of an LLC in statute except in cases of extreme fraud, which is one more reason why I prefer NV for LLCs when possible.
I've posted extensively on these subjects in the law and legal forum, review the longer posts dealing with insurance, LLC's, and related topics. In essance I suggest a three tier structure where you and your partners/family own NV LLCs (top level) that do nothing but own other NV LLCs (mid-level) and the mid-level LLCs then own other LLCs (low level) in other states or NV as appropriate. The low level LLCs own the property and businesses. Why? even if the veil is pierced on a low level LLC it is owned by one or more NV LLCs (mid level) which are very hard to enforce judgements against. Also, the top level and mid level LLCs do not engage in any business that could generate a suit against them (except legitimate borrowing from lenders) which makes this kind of structure even harder to attack in court.
Are LP useful? Yes, in specific circumstances they are very useful, though the LLC has all the same benefits and no general partner. Regarding peircing the veil of a LP or LLC? Depends on the state of incorporation, for example CO holds LLCs to the same standards as corporations (bad) while NV specifically prohibits peircing the veil of an LLC in state law. Likewise CO is a poorer choice for LPs than other states but an LP may be superior for your needs in CO as compared to a CO LLC.
As Mr. Merchant pointed out you need professional advice specific to your situation. However, I would add that you need to research LLCs, Corporations, LPs, and S corps and the laws of various states regarding each to have a good base of knowledge from which to ask the more advanced questions that arise in the asset protection area. For example, how do I structure my operating/partnership agreement?
Once you know the major issues you are better qualified to judge if the attorney you are seeking advice from actually knows what they are about or is just selling a cookie-cutter approach to make money.